Wildlife Landscape ↔ relates to ↔ Energy Utilities

power generation. It is currently the U.S.'s largest wholesaler of water, bringing water to more than 31 million people, and providing one in five Western farmers with irrigation water for 10 million acres of farmland, which produce 60% of the nation's vegetables and 25% of its fruits and nuts. The bureau is also the second largest producer of hydroelectric power in the western U.S. On June 17, 1902, in accordance with the Reclamation Act, Secretary of the Interior Ethan Allen Hitchcock established the U.S. Reclamation Service within the U.S. Geological Survey (USGS). The new Reclamation Service studied potential water development projects in each western state with federal lands. Revenue from sale of federal lands was the initial source of the program's funding.

From 1902 to 1907, Reclamation began about 30 projects in Western states. Then, in 1907, the Secretary of the Interior separated the Reclamation Service from the USGS and created an independent bureau within the Department of the Interior. Frederick Haynes Newell was appointed the first director of the new bureau. Beginning with the third person to take over the direction of Reclamation in 1923, David W. Davis, the title was changed from Director to Commissioner. In the early years, many projects encountered problems: lands or soils included in projects were unsuitable for irrigation; land speculation sometimes resulted in poor settlement patterns; proposed repayment schedules could not be met by irrigators who had high land-preparation and facilities-construction costs; settlers were inexperienced in irrigation farming; waterlogging of irrigable lands required expensive drainage projects; and projects were built in areas which could only grow low-value crops. In 1923 the agency was renamed the "Bureau of Reclamation". In 1924, however, in the face of increasing settler unrest and financial woes, the "Fact Finder's Report" spotlighted major problematic issues; the Fact Finders Act in late 1924 sought to resolve some of these problems. In 1928 Congress authorized the Boulder Canyon (Hoover Dam) Project, and large appropriations began, for the first time, to flow to Reclamation from the general funds of the United States. The authorization came only after a hard-fought debate about the pros and cons of public power versus private power. The heyday of Reclamation construction of water facilities occurred during the Depression and the 35 years after World War II. From 1941 to 1947, Civilian Public Service labor was used to carry on projects otherwise interrupted by the war effort. The last major authorization for construction projects occurred in the late 1960s, while a parallel evolution and development of the American environmental movement began to result in strong opposition to water development projects. Even the 1976 failure of Teton Dam as it filled for the first time did not diminish Reclamation's strong international reputation in water development circles. However, this first and only failure of a major Reclamation Bureau dam led to subsequent strengthening of its dam-safety program to avoid similar problems. Even so, the failure of Teton Dam, the environmental movement, and the announcement of President Carter's "hit list" on water projects profoundly affected the direction of Reclamation's programs and activities. Reclamation operates about 180 projects in the 17 western states. The total Reclamation investment for completed project facilities in September 1992 was about $11 billion. Reclamation projects provide agricultural, household, and industrial water to about one‑third of the population of the American West. About 5% of the land area of the West is irrigated, and Reclamation provides water to about one-fifth of that area, some 9,120,000 acres (37,000 km2) in 1992. Reclamation is a major American generator of electricity. As of 2007, Reclamation had 58 power plants on‑line and generated 125,000 GJ of electricity. From 1988 to 1994, Reclamation underwent major reorganization as construction on projects authorized in the 1960s and earlier drew to an end. Reclamation wrote that "The arid West essentially has been reclaimed. The major rivers have been harnessed and facilities are in place or are being completed to meet the most pressing current water demands and those of the immediate future". Emphasis in Reclamation programs shifted from construction to operation and maintenance of existing facilities. Reclamation's redefined official mission is to "manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public".

the nation's vegetables and 25% of its fruits and nuts. The bureau is also the second largest producer of hydroelectric power in the western U.S. On June 17, 1902, in accordance with the Reclamation Act, Secretary of the Interior Ethan Allen Hitchcock established the U.S. Reclamation Service within the U.S. Geological Survey (USGS). The new Reclamation Service studied potential water development projects in each western state with federal lands. Revenue from sale of federal lands was the initial source of the program's funding.

, coined the name "Treasure Valley" in 1959 to reflect the treasure chest of resources and opportunities that the region offered. The valley has a very diverse terrain, from sage flatlands, to mesas, agricultural areas, and urbanized areas. As the Boise Metropolitan Area grows, more and more undeveloped and agricultural land is being urbanized. History Settling the region The tribes that roamed the area, specifically, were the Northern Paiute and Shoshone. In 1834, Thomas McKay built the original Fort Boise, in the area near present-day Parma, which was run for a time by Francois Payette. It later was moved because of flooding troubles and was abandoned in 1854. The Oregon Trail runs through the Treasure Valley. The valley was settled for the most part by ranchers and farmers, initially to supply the gold and silver mining communities in the higher elevations nearby: Idaho City in the Boise Basin and Silver City in the Owyhees. A new Fort Boise was constructed by the U.S. Army in 1863 in present-day Boise, from which the city grew.

The Treasure Valley is a valley in the western United States, primarily in southwestern Idaho, where the Payette, Boise, Weiser, Malheur, and Owyhee rivers drain into the Snake River. It includes all the lowland areas from Vale in rural eastern Oregon to Boise, and is the most populated area in Idaho. Historically, the valley had been known as the Lower Snake River Valley or the Boise River Valley. Pete Olesen, president of the valley's association of local Chambers of Commerce, coined the name "Treasure Valley" in 1959 to reflect the treasure chest of resources and opportunities that the region offered. The valley has a very diverse terrain, from sage flatlands, to mesas, agricultural areas, and urbanized areas.

icultural land is being urbanized. History Settling the region The tribes that roamed the area, specifically, were the Northern Paiute and Shoshone. In 1834, Thomas McKay built the original Fort Boise, in the area near present-day Parma, which was run for a time by Francois Payette. It later was moved because of flooding troubles and was abandoned in 1854. The Oregon Trail runs through the Treasure Valley. The valley was settled for the most part by ranchers and farmers, initially to supply the gold and silver mining communities in the higher elevations nearby: Idaho City in the Boise Basin and Silver City in the Owyhees. A new Fort Boise was constructed by the U.S. Army in 1863 in present-day Boise, from which the city grew.

began in 1941 and experienced numerous challenges with materials, fuel, and labor shortages during World War II. Work was halted for over nine months beginning in late December 1942. The Reclamation Act of 1902 had racial exclusions on labor which were strictly adhered to until Congress changed the law in 1943. This allowed Japanese American internees to work on Reclamation projects; Anderson Ranch utilized internees from the Minidoka War Relocation Center, northeast of Twin Falls. The South Fork of the Boise River originates in the Smoky Mountains north of Fairfield. Its watershed includes portions of the Smoky Mountains, Soldier Mountains, Boise National Forest, and Sawtooth National Forest. Below the dam, the South Fork flows northwestward into the reservoir behind the concrete Arrowrock Dam, completed in 1915. The Bureau of Reclamation and Idaho Water Resource Board are working on raising the dam by six feet (1.8 m), resulting in approximately 29,000 acre-feet (35,800,000 m3) of new storage space.

d operated by the U.S. Bureau of Reclamation. When completed 76 years ago in 1950, Anderson Ranch was the tallest dam of its type in the world. Its primary purpose is to provide irrigation water for agriculture, with a secondary purpose of hydroelectric power. Its generating capacity was increased from 27 to 40 MW in 1986. Its reservoir has a spillway elevation of 4,196 feet (1,280 m) above sea level. The construction of the dam began in 1941 and experienced numerous challenges with materials, fuel, and labor shortages during World War II. Work was halted for over nine months beginning in late December 1942. The Reclamation Act of 1902 had racial exclusions on labor which were strictly adhered to until Congress changed the law in 1943. This allowed Japanese American internees to work on Reclamation projects; Anderson Ranch utilized internees from the Minidoka War Relocation Center, northeast of Twin Falls. The South Fork of the Boise River originates in the Smoky Mountains north of Fairfield. Its watershed includes portions of the Smoky Mountains, Soldier Mountains, Boise National Forest, and Sawtooth National Forest. Below the dam, the South Fork flows northwestward into the reservoir behind the concrete Arrowrock Dam, completed in 1915. The Bureau of Reclamation and Idaho Water Resource Board are working on raising the dam by six feet (1.8 m), resulting in approximately 29,000 acre-feet (35,800,000 m3) of new storage space.

Anderson Ranch Dam is an earth rockfill type dam in the western United States, on the South Fork of the Boise River in southwestern Idaho. In Elmore County northeast of Mountain Home, it is several miles north of U.S. Route 20 and operated by the U.S. Bureau of Reclamation. When completed 76 years ago in 1950, Anderson Ranch was the tallest dam of its type in the world. Its primary purpose is to provide irrigation water for agriculture, with a secondary purpose of hydroelectric power. Its generating capacity was increased from 27 to 40 MW in 1986. Its reservoir has a spillway elevation of 4,196 feet (1,280 m) above sea level. The construction of the dam began in 1941 and experienced numerous challenges with materials, fuel, and labor shortages during World War II. Work was halted for over nine months beginning in late December 1942. The Reclamation Act of 1902 had racial exclusions on labor which were strictly adhered to until Congress changed the law in 1943. This allowed Japanese American internees to work on Reclamation projects; Anderson Ranch utilized internees from the Minidoka War Relocation Center, northeast of Twin Falls. The South Fork of the Boise River originates in the Smoky Mountains north of Fairfield. Its watershed includes portions of the Smoky Mountains, Soldier Mountains, Boise National Forest, and Sawtooth National Forest. Below the dam, the South Fork flows northwestward into the reservoir behind the concrete Arrowrock Dam, completed in 1915. The Bureau of Reclamation and Idaho Water Resource Board are working on raising the dam by six feet (1.8 m), resulting in approximately 29,000 acre-feet (35,800,000 m3) of new storage space.

nd Elmore counties, upstream of the Lucky Peak Dam and reservoir. The spillway elevation for Arrowrock is 3,219 feet (981 m) above sea level and its primary purpose is to provide irrigation water for agriculture. The dam was designated as a National Historic Civil Engineering Landmark by the American Society of Civil Engineers in 2016, and is operated by the U.S. Bureau of Reclamation. Preparations In 1910, the Reclamation Service began to consider another storage facility farther east on the Boise River. After several surveys, engineers decided upon the Arrowrock site which had previously been the site of a private irrigation venture under the direction of Arthur De Wint Foote yet failed for lack of funding. The Arrowrock site is at the confluence of the main channel and the south fork. That was to be the most ambitious project to date for Reclamation. At 348 feet (106 m), Arrowrock would be the largest concrete arch dam in the world. Prior to construction, considerable preparatory work would need to be completed. As the structure was some twenty miles (32 km) upstream from the Boise River Diversion Dam, routing supplies to the worksite would be a massive undertaking unto itself. The Reclamation Service elected to construct a new rail line on the old wagon road leading north to Idaho City. The railroad would begin at the Barberton mill near the Diversion Dam and extend to through a winding canyon up to Arrowrock. Even before the dam had been approved, Reclamation began work on the rail line. Some significant problems existed with construction of the railroad. The Barberton Lumber Company owned the road's right-of-way. That meant that the Reclamation Service needed to come to an agreement over ownership of the rail line. In an unprecedented move, the government agreed to lease the track from Barberton but run the actual locomotive. Part of this agreement stipulated that the line would remain a common carrier. That made the Arrowrock & Boise Railroad the first publicly owned line in the nation. The Service hid this fact from President William Howard Taft when it applied for the Arrowrock Dam's approval. Fortunately for Reclamation, Taft failed to recognize the loophole and in June 1910, the entire project went forward. However, when the Oregon Shortline refused to honor the pact between Barberton and Reclamation, the Arrowrock & Boise terminal was reduced to a field just outside the Barber lumberyard. On August 22, 1910, the entire deal was finalized and work began on the line to the Arrowrock site. Salt Lake City's Manly Brothers won the contract for grading the Arrowrock & Boise road in May 1911. The government called for force account to lay the track from Barber to the work site. Although the construction was delayed several times by the shortage of railroad ties, workers finished the track in early November. By most accounts, the trip through the canyon was a very long and harrowing event. For the first several months, riders were asked to disembark at the unfinished Gooseneck Bridge while the cars were winched across one at a time. However, once they arrived, most passengers were surprised by what they found. Not only was the view breathtaking but the "work" camp offered amenities that were unavailable to some residents of the Treasure Valley. Not only was the site fully powered, but also it provided a central heating plant, running water and an efficient sewage system. Along with the Reclamation offices, the Arrowrock camp carried a hospital, mess hall, post office, and hotel. Workers and visitors were offered lodging in the site's hotel, bunkhouses, or cottages. In addition to the outdoor recreational activities, the camp also operated a YMCA, school, and dancehall. At the peak of construction, some 1,400 people had called Arrowrock home, including some 200 families. To provide power for the site, Reclamation retrofitted The Boise River Diversion Dam with a small powerhouse. Finished in 1912, the plant's three generators produced 1,500 kilowatts of electricity for Arrowrock's camp, sawmills, and giant cement mixers. The German made Allis-Chalmers 725 horsepower (541 kW) turbines, the first in the world to be built with a vertical shaft design. Along with the power lines, government workers hung a two-way phone cable to connect Arrowrock with the outside world. In 1976, the power plant was added to the National Register of Historic Places. After being refurbished by the Bonneville Power Administration in 2002, it is now on ready reserve status and occasionally provides surplus power during times of peak demand. Special care was made to maintain the historic qualities of the powerhouse.

Arrowrock is 3,219 feet (981 m) above sea level and its primary purpose is to provide irrigation water for agriculture. The dam was designated as a National Historic Civil Engineering Landmark by the American Society of Civil Engineers in 2016, and is operated by the U.S. Bureau of Reclamation. Preparations In 1910, the Reclamation Service began to consider another storage facility farther east on the Boise River. After several surveys, engineers decided upon the Arrowrock site which had previously been the site of a private irrigation venture under the direction of Arthur De Wint Foote yet failed for lack of funding. The Arrowrock site is at the confluence of the main channel and the south fork. That was to be the most ambitious project to date for Reclamation. At 348 feet (106 m), Arrowrock would be the largest concrete arch dam in the world. Prior to construction, considerable preparatory work would need to be completed. As the structure was some twenty miles (32 km) upstream from the Boise River Diversion Dam, routing supplies to the worksite would be a massive undertaking unto itself. The Reclamation Service elected to construct a new rail line on the old wagon road leading north to Idaho City. The railroad would begin at the Barberton mill near the Diversion Dam and extend to through a winding canyon up to Arrowrock. Even before the dam had been approved, Reclamation began work on the rail line. Some significant problems existed with construction of the railroad. The Barberton Lumber Company owned the road's right-of-way. That meant that the Reclamation Service needed to come to an agreement over ownership of the rail line. In an unprecedented move, the government agreed to lease the track from Barberton but run the actual locomotive. Part of this agreement stipulated that the line would remain a common carrier. That made the Arrowrock & Boise Railroad the first publicly owned line in the nation. The Service hid this fact from President William Howard Taft when it applied for the Arrowrock Dam's approval. Fortunately for Reclamation, Taft failed to recognize the loophole and in June 1910, the entire project went forward. However, when the Oregon Shortline refused to honor the pact between Barberton and Reclamation, the Arrowrock & Boise terminal was reduced to a field just outside the Barber lumberyard. On August 22, 1910, the entire deal was finalized and work began on the line to the Arrowrock site. Salt Lake City's Manly Brothers won the contract for grading the Arrowrock & Boise road in May 1911. The government called for force account to lay the track from Barber to the work site. Although the construction was delayed several times by the shortage of railroad ties, workers finished the track in early November. By most accounts, the trip through the canyon was a very long and harrowing event. For the first several months, riders were asked to disembark at the unfinished Gooseneck Bridge while the cars were winched across one at a time. However, once they arrived, most passengers were surprised by what they found. Not only was the view breathtaking but the "work" camp offered amenities that were unavailable to some residents of the Treasure Valley. Not only was the site fully powered, but also it provided a central heating plant, running water and an efficient sewage system. Along with the Reclamation offices, the Arrowrock camp carried a hospital, mess hall, post office, and hotel. Workers and visitors were offered lodging in the site's hotel, bunkhouses, or cottages. In addition to the outdoor recreational activities, the camp also operated a YMCA, school, and dancehall. At the peak of construction, some 1,400 people had called Arrowrock home, including some 200 families. To provide power for the site, Reclamation retrofitted The Boise River Diversion Dam with a small powerhouse. Finished in 1912, the plant's three generators produced 1,500 kilowatts of electricity for Arrowrock's camp, sawmills, and giant cement mixers. The German made Allis-Chalmers 725 horsepower (541 kW) turbines, the first in the world to be built with a vertical shaft design. Along with the power lines, government workers hung a two-way phone cable to connect Arrowrock with the outside world. In 1976, the power plant was added to the National Register of Historic Places. After being refurbished by the Bonneville Power Administration in 2002, it is now on ready reserve status and occasionally provides surplus power during times of peak demand. Special care was made to maintain the historic qualities of the powerhouse.

U.S. Bureau of Reclamation Archived 2012-09-26 at the Wayback Machine - Arrowrock Dam U.S. Bureau of Reclamation - major storage reservoirs in the Boise & Payette River basins - current levels & flows Historic American Engineering Record (HAER) documentation, filed under Boise River, Twin Springs, Boise County, ID: HAER No. ID-27, "Arrowrock Dam", 101 photos, 123 data pages, 11 photo caption pages HAER No.

and four navigation dams on its lower section created a shipping channel to Lewiston, Idaho – the furthest inland seaport on the West Coast. While dam construction, commercial fishing and other human activities have greatly reduced anadromous fish populations since the late 19th century, the Snake River watershed is still considered important habitat for these fish. The Snake and its tributary, the Salmon River, host the longest sockeye salmon run in the world, stretching 900 miles (1,400 km) from the Pacific to Redfish Lake in Idaho. Since the 1950s, public agencies, tribal governments and private utilities have invested heavily in fishery restoration and hatchery programs, with limited success.

sh. The Snake and its tributary, the Salmon River, host the longest sockeye salmon run in the world, stretching 900 miles (1,400 km) from the Pacific to Redfish Lake in Idaho. Since the 1950s, public agencies, tribal governments and private utilities have invested heavily in fishery restoration and hatchery programs, with limited success.

As gold mining declined in the late 19th century, the wheat industry boomed in the Palouse of southeast Washington. By the 1870s, the Oregon Steam Navigation Company was operating seven steamboats transporting grain from the Snake River to lower Columbia River ports. These were the Harvest Queen, John Gates, Spokane, Annie Faxon, Mountain Queen, R.R. Thompson, and Wide West. In the 1890s, a huge copper deposit was discovered at Eureka Bar in Hells Canyon. Several ships transported ore from there to Lewiston, including Imnaha, Mountain Gem, and Norma. In 1893 the Annie Faxon suffered a boiler explosion and sank on the Snake below Lewiston, killing five people. Starting in the 1880s, the Army Corps began dredging the Snake River below Lewiston to maintain a 5-foot (1.5 m) deep navigation channel. River traffic declined rapidly once railroads arrived. By 1899, the Union Pacific line along the south bank of the Snake River had reached Riparia, Washington. It then joined forces with the Northern Pacific Railroad, which was building a line along the north bank, to build the shared Camas Prairie Railroad the rest of the way to Lewiston, which it reached in 1908. The Open River Transportation Company, which operated steamboats between Lewiston and Celilo Falls on the Columbia, went bankrupt in 1912. The 1915 completion of the Celilo Canal made it much easier for boats from the upper Columbia and Snake to reach Portland, and the Columbia River Transportation Company began operating a water route between Lewiston and Portland. Still, steamboats were unable to compete with railroads on speed and efficiency. The last steamboat on the lower Snake ran in 1920. Once the railroads monopolized grain shipments, they raised shipping rates, to farmers' consternation. In 1934, political activist Herbert G. West organized the Inland Empire Waterways Association (IEWA), to promote an "open river" – a deep-water shipping channel on the Snake and Columbia Rivers that could compete with rail. The IEWA initially pushed for improvements such as bigger locks at Bonneville Dam in 1938 and the construction of McNary Dam on the Columbia, which would improve navigation to the mouth of the Snake. In 1941 a bill was first introduced in Congress authorizing the Army Corps to develop the lower Snake River. The 1941 bill failed, but after several years of debate, Congress finally authorized the Snake River development in 1945. Early plans included anywhere from six to ten low dams for the lower Snake. Eventually this was reduced to four bigger dams, which would lower costs, but would require what at the time were the tallest navigation locks in the world, at over 100 feet (30 m). Tribes, state wildlife agencies and the fishing industry opposed the dams, arguing that they would kill too many salmon. In 1947, the U.S. Department of the Interior proposed a ten-year moratorium on dam construction while the fishery problem was studied. With the onset of the Cold War, rising electricity demand in the Pacific Northwest – particularly at the nearby Hanford nuclear site – turned the project's focus towards hydropower. By 1948, the Army Corps estimated that over 80 percent of the economic benefits would come from power, and only 15 percent from navigation. Dam opponents countered that if the primary objective was now power, other dam sites existed in the Northwest that would have less impact on fish. These objections proved futile, as the lower Snake River dams were already authorized, and the federal government had little interest in studying alternatives. While opponents continued to stall the project for a few more years, Washington Senator Warren G.

Boise National Forest is a National Forest covering 2,203,703 acres (8,918.07 km2) of the U.S. state of Idaho. Created on July 1, 1908, from part of Sawtooth National Forest, it is managed by the U.S. Forest Service as five units: the Cascade, Emmett, Idaho City, Lowman, and Mountain Home ranger districts. The Idaho Batholith underlies most of Boise National Forest, forming the forest's Boise, Salmon River, and West mountain ranges; the forest reaches a maximum elevation of 9,730 feet (2,970 m) on Steel Mountain. Common land cover includes sagebrush steppe and spruce-fir forests; there are 9,600 miles (15,400 km) of streams and rivers and 15,400 acres (62 km2) of lakes and reservoirs. Boise National Forest contains 75 percent of the known populations of Sacajawea's bitterroot, a flowering plant endemic to Idaho. The Shoshone people occupied the forest before European settlers arrived in the early 19th century. Many of the early settlers were trappers and prospectors before gold was discovered in 1862. After the 1860s Boise Basin gold rush ended, mining of tungsten, silver, antimony, and gold continued in the forest until the mid-twentieth century. Recreation facilities include over 70 campgrounds, whitewater and flatwater boating, cabin rentals, and 1,300 miles (2,100 km) of trails for hiking, biking, horseback riding, and motorized off-road vehicle use.

s a maximum elevation of 9,730 feet (2,970 m) on Steel Mountain. Common land cover includes sagebrush steppe and spruce-fir forests; there are 9,600 miles (15,400 km) of streams and rivers and 15,400 acres (62 km2) of lakes and reservoirs. Boise National Forest contains 75 percent of the known populations of Sacajawea's bitterroot, a flowering plant endemic to Idaho. The Shoshone people occupied the forest before European settlers arrived in the early 19th century. Many of the early settlers were trappers and prospectors before gold was discovered in 1862. After the 1860s Boise Basin gold rush ended, mining of tungsten, silver, antimony, and gold continued in the forest until the mid-twentieth century. Recreation facilities include over 70 campgrounds, whitewater and flatwater boating, cabin rentals, and 1,300 miles (2,100 km) of trails for hiking, biking, horseback riding, and motorized off-road vehicle use.

Archaeological evidence indicates that human habitation in Idaho began towards the end of the last ice age: bone fragments about 10,000 years old have been found in Wilson Butte Cave, an inflationary cave on the Snake River Plain believed to have been occupied by indigenous people until as recently as the 17th century. A change of climate around 7000 years ago dried up much of the Great Basin, forcing the Shoshone people northward into the mountainous areas of central Idaho. Most of what is now Boise National Forest was sparsely inhabited by Native Americans, and several archaeological sites, including campsites, rock shelters, burial grounds, and pictographs have been found along rivers in the area. Trappers and fur traders of European descent first arrived in the area in the early 1800s, starting with John Jacob Astor's Pacific Fur Company in October 1811. Donald Mackenzie and Francois Payette trapped in the area of Boise National Forest in 1819. By 1840, the fur trade was coming to an end, but the westward migration on the Oregon Trail, which passed south of the forest, was beginning. The first settlers moved into the mountains in the 1860s after gold was discovered in Idaho, which forced many of the Shoshone out and led to conflicts throughout the state, including the Bannock War in southern Idaho. Prospectors George Grimes and Moses Splawn were the first to discover gold in the forest at the eponymous Grimes Creek on August 2, 1862. Subsequent gold discoveries at Rocky Bar in 1863 and Atlanta in 1864 increased the rush of people to Idaho, and in 1863 Idaho City, with a population of 6,267, surpassed Portland, Oregon as the largest city in the Pacific Northwest. The Idaho gold rush was largely over by 1870, and the population of the Boise Basin fell from 16,000 to 3,500. In 1898 the forest's first gold dredge was built in Placerville and followed by several others. By 1951, when the last dredges shut down, at least 2.3 million ounces (65.2 million grams) of gold had been produced from the Boise Basin area. Silver was mined along the Crooked River from 1882 until 1921, but a silver mine at Silver Mountain proved unsuccessful. Following a shortage of mercury during World War II, mines in the Stibnite area became the country's largest producer of tungsten and second largest source of mercury. The most important known placer deposit of niobium and tantalum in the United States is located in Bear Valley. From 1953 until 1959, dredges there produced $12.5 million ($138 million today) in niobium, tantalum, and uranium. Other minerals mined in the forest include antimony and molybdenum. U.S. Forest Service Boise National Forest was created on July 1, 1908, from part of Sawtooth National Forest, and originally covered 1,147,360 acres (4,643.2 km2). By the Forest Reserve Act of 1891, the U.S. Congress granted the U.S. President the authority to establish forest reserves out of Public Domain Lands that were subject to disposal (homesteads, sales, etc.) administered by the United States General Land Office, which had been placed under the authority of the U.S. Department of the Interior in 1849. With the passage of the Transfer Act of 1905, forest reserves were transferred to the U.S. Department of Agriculture in the newly created U.S. Forest Service. Present-day Boise National Forest was first protected as part of two forest reserves by proclamations issued by President Theodore Roosevelt: Sawtooth Forest Reserve (created on May 29, 1905, and expanded on November 6, 1906) and Payette Forest Reserve (created on June 3, 1905). After forest reserves were renamed national forests in 1908, Boise National Forest was split from Sawtooth National Forest into an independent national forest. Emile Grandjean was the forest's first supervisor, serving from 1908 to 1922. On April 1, 1944, the entirety of what was then Payette National Forest was transferred to Boise National Forest, and simultaneously Weiser and Idaho national forests were combined to reestablish the present-day Payette National Forest, which is to the north of Boise National Forest. In 1933 the Boise Basin Experimental Forest was created on 8,740 acres (35.4 km2) of the forest near Idaho City to study the management of ponderosa pine. The Lucky Peak Nursery was established in 1959 to produce trees for planting on burned or logged lands on the national forests of the Intermountain region. After the creation of the Civilian Conservation Corps (CCC) in 1933, nine camps and eight subcamps were set up in Boise National Forest, but the number of camps was reduced from 1934 until the program was closed in 1942.

ise, as well as part of the western Snake River Plain. The watershed encompasses approximately 4,100 square miles (11,000 km2) of highly diverse habitats, including alpine canyons, forest, rangeland, agricultural lands, and urban areas. Description The Boise River rises in three separate forks in the Sawtooth Range at elevations exceeding 10,000 feet (3,050 m), and is formed by the confluence of its North and Middle forks. The North Fork, 50 miles (80 km) long, rises in the Sawtooth Wilderness Area, along the Boise–Elmore county line, 60 miles (100 km) northeast of Boise. It flows generally southwest through the remote mountains in the Boise National Forest. The Middle Fork, approximately 52 miles (84 km) in length, rises within 12 miles (19 km) of the North Fork in the southern Sawtooth Wilderness Area in northeastern Elmore County. It flows west-southwest near the town of Atlanta, joining the North Fork to form the Boise River, approximately 15 miles (24 km) southeast of Idaho City.

History The river was called "Reed's River" in the early 19th century, named after Pacific Fur Company employee John Reed, who explored parts of the river throughout 1813 and 1814. The river is diverted to canals for irrigation on the plain west of what is now Boise. The dams that form the mountain reservoirs were constructed as part of the Bureau of Reclamation's "Boise Project" to provide agricultural irrigation, hydroelectricity, drinking water, and flood control to Boise and the Treasure Valley. The major projects' initial completion dates were: 1909 – Boise River Diversion Dam & New York Canal 1915 – Arrowrock Dam 1950 – Anderson Ranch Dam - (S. Fork) 1955 – Lucky Peak Dam - (U.S. Army Corps of Engineers) The Boise River was proposed for 50 years for a dam at Twin Springs, culminating in a 1966 Project Travois proposal, which would have used nuclear explosives to either create large amounts of rockfill aggregate for dam construction, or to induce a landslide that would have much the same effect. Project Travois was a component of Project Plowshare.

Recreation The river is a popular destination for floating, specifically on the Boise greenbelt. Tubers and floaters launch at Barber Park and land at Ann Morrison Park, between major irrigation diversion dams. Several minor diversion weirs are passed as well as several bridges on the 6-mile (10 km) trip. Water skiing is popular above the dam at the Lucky Peak Reservoir. On the lower (warmwater) course of the river, low summer flows and poorer water quality from agricultural runoff limit fishery production. This section of river supports a fair fishery for largemouth bass, smallmouth bass, and channel catfish. Upstream from Star, the river is a coldwater stream and supports a greater variety of fish. The most prevalent species on this section is mountain whitefish, as well as hatchery-reared rainbow trout, wild rainbow trout, and brown trout. Upstream from Lucky Peak and Arrowrock reservoirs, the river and its tributaries contain excellent populations of wild rainbow trout, mountain whitefish, and bull trout.

rs about a quarter of Idaho. Three major volcanic buttes dot the plain east of Arco, the largest being Big Southern Butte. Most of Idaho's major cities are in the Snake River Plain, as is much of its agricultural land. Geology The Snake River Plain can be divided into three sections: western, central, and eastern. The western Snake River Plain is a large tectonic graben or rift valley filled with several kilometers of Lake Idaho sediments; the sediments are underlain by rhyolite and basalt, and overlain by basalt. The western plain began to form around 11–12 Ma (million years ago) with the eruption of rhyolite lavas and ignimbrites. The western plain is not parallel to North American Plate motion and lies at a high angle to the central and eastern Snake River Plain.

e of Wyoming to the Idaho-Oregon border. The plain is a wide, flat bow-shaped depression and covers about a quarter of Idaho. Three major volcanic buttes dot the plain east of Arco, the largest being Big Southern Butte. Most of Idaho's major cities are in the Snake River Plain, as is much of its agricultural land. Geology The Snake River Plain can be divided into three sections: western, central, and eastern. The western Snake River Plain is a large tectonic graben or rift valley filled with several kilometers of Lake Idaho sediments; the sediments are underlain by rhyolite and basalt, and overlain by basalt. The western plain began to form around 11–12 Ma (million years ago) with the eruption of rhyolite lavas and ignimbrites. The western plain is not parallel to North American Plate motion and lies at a high angle to the central and eastern Snake River Plain.

The Snake River Plain can be divided into three sections: western, central, and eastern. The western Snake River Plain is a large tectonic graben or rift valley filled with several kilometers of Lake Idaho sediments; the sediments are underlain by rhyolite and basalt, and overlain by basalt. The western plain began to form around 11–12 Ma (million years ago) with the eruption of rhyolite lavas and ignimbrites. The western plain is not parallel to North American Plate motion and lies at a high angle to the central and eastern Snake River Plain.

Boise (locally also ) is the capital and most populous city in the U.S. state of Idaho. It is the county seat of Ada County. The population of the city was 235,685 at the 2020 census. The Boise metropolitan area, located in the Treasure Valley, includes five counties of Idaho with an estimated population of 846,000, the most populous metropolitan area in Idaho and 95th-most populous in the United States. Located on the Boise River in southwestern Idaho, it is 41 miles (66 km) east of the Oregon border and 110 miles (177 km) north of the Nevada border. Downtown Boise's elevation is 2,704 feet (824 m) above sea level. Boise is home to major employers in the technology, manufacturing, and service sectors, including companies such as Micron Technology and Hewlett-Packard.

an area in Idaho and 95th-most populous in the United States. Located on the Boise River in southwestern Idaho, it is 41 miles (66 km) east of the Oregon border and 110 miles (177 km) north of the Nevada border. Downtown Boise's elevation is 2,704 feet (824 m) above sea level. Boise is home to major employers in the technology, manufacturing, and service sectors, including companies such as Micron Technology and Hewlett-Packard.

...that the military should continue killing Indians 'until the last Indian in the Territories was either on his reservation or enriched the sagebrush with his decaying carcass.' ...if the Indians refused to move there, 'they will be killed or put on the reservation by force, and certainly shot if they don't stay there.' Furthermore, the editor continues, 'The idea that the Indians have any right to the soil is ridiculous. ...They have no more rights to the soil of the Territories of the United States than wolves or coyotes...' This would be our plan of establishing friendship upon an eternal basis with our Indians: Let all the hostile bands of Idaho Territory be called in (they will not be caught in any other manner) to attend a grand treaty; plenty of blankets and nice little trinkets distributed among them; plenty of grub on hand; have a real jolly time with them; then just before the big feast put strychnine in their meat and poison to death the last mother's son of them. At the same time, native warriors around the valley, under the leadership of Howluck also known as "Bigfoot" among white settlers, among others, waged an escalating and intensified guerrilla campaign of harassment of passerby caravans along the Oregon Trail. The United States Army also escalated and intensified "punitive expeditions" against formations of warriors and against civilian communities as well. This marked the start of the "unofficial" Snake War in 1866. This war lasted until 1868, and is statistically the deadliest of the Indian Wars in the West in terms of casualties. In the end, 1,762 men were counted as the casualties of this war from both sides. In 1868, Fort Hall Indian Reservation was established in Southeastern Idaho, about 220 miles upstream, according to the terms of Fort Bridger Treaty. The Boise Valley Shoshone and Bannock Tribes were not party to this treaty. Nevertheless, in April 1869, the United States Military embarked on a campaign of "Removal, rounding up of natives in the region including in and around Boise, and expelling them with cavalry escort to Fort Hall Indian Reservation. This period is known among the Shoshone and Bannock people as Idaho's Trail of Tears. Some of the natives managed to escape, and they ran to either Duck Valley or Fort McDermitt in Nevada. Incorporation and growth Boise's early growth was significantly driven by its role in supplying the nearby gold towns that sprung up in the 1860s northeast and then southwest of the town. Miners sometimes wintered in Boise and a number of early prominent businessmen were miners who settled in town in the years after the gold rush waned. By 1864 substantial agricultural production was underway on easily irrigated lands near the river and three canal companies had been incorporated. Early transportation improvements were largely a result of toll road franchises awarded by the territorial legislature starting in the 1860s. These first ran from Fort Boise to the mining centers in the Boise Basin and east to Rocky Bar and to Rattlesnake Station where they connected to the Oregon Trail. Territorial census records from a special 1864 enumeration list the population of Boise as 1,658, and an act of December 12, 1864, was the first attempt by the Idaho Territorial Legislature to incorporate the city. This was rejected by voters the following March. Two more unsuccessful attempts were made to organize a city administration by election before the 1866 version of the city charter was approved by voters on January 6, 1868. The growing number of homes and businesses, for which owners wanted proper legal title, may have contributed to the eventual success of incorporation. All of these rejected efforts to incorporate the city came after Boise had been controversially made the state capital in 1864 over strong opposition from northern Idaho interests. This decision reflected the rapid shift of population growth from north to south after the discovery of gold in southern Idaho. By 1868 Boise had over 400 permanent buildings with a wide range of commercial services. 1868 also marked the formal beginning of a long advocacy for railroad connections to other Idaho communities and, just as importantly, to other growing cities in the west such as Portland, Oregon. Competing railroad and western state government interests frustrated these efforts for many years. Designed by Alfred B. Mullett, the U.S. Assay Office at 210 Main Street was built in 1871 and today is a National Historic Landmark. It first began accepting gold and silver for purchase on March 2, 1872, largely eliminating the need to transport ore to the mint in San Francisco. A territorial penitentiary, now known as the Old Idaho State Penitentiary, opened the same month several miles east of town. Mining continued to be important to Boise's economic growth and periodic booms contributed to population growth as well, though production of gold and silver probably peaked in the 1860s. 1882's gold and silver production of $3,500,000 declined to $1,488,315 (including lead) by 1899. Boise began to earn its City of Trees nickname in this period with a popular focus on a range of tree planting projects. Thomas J. Davis planted several thousand fruit trees in 1864 and several other early businessmen either founded nurseries or orchards of their own. In the 1870s tree planting began in earnest in downtown Boise led by prominent hotels as well as businessmen and residents. In 1907 Davis donated 43 acres of his orchard property to the city for use as a park in the name of his wife Julia. Commercial agriculture continued to expand, but was slowed by the lack of reliable rail links to regional and national markets and by a lack of large scale irrigation projects, which themselves were often tied to hoped-for railroad projects for financing. A.D. Foote, a successful mining engineer, drew up plans to irrigate up to 500,000 acres immediately south of Boise in 1882, but progress was halting and smaller farms were the norm until after the turn of the century with most located near to the river bottom where soil was productive and irrigation more easily achieved. Fruit orchards proliferated and sugar beets, still an important agricultural industry in Idaho, began to be widely cultivated in the 1890s. Cattle and sheep farming became increasingly important as the century closed. With the exception of dairy, most livestock products were exported from Idaho, unlike other agricultural products which were still largely scaled to support local markets. The timber industry also increasingly thrived in the Boise market in the 1880s and 1890s. Large quantities of timber were exported from elsewhere in Idaho, but a growing Boise supported the expansion of Alexander Rossi's sawmill, first established in 1865. Prominent early Boisean William Ridenbaugh had inherited control of the canal now bearing his name from his uncle William Morris in 1878 and later partnered with Rossi to expand the sawmill capacity under the name Rossi and Ridenbaugh Lumber Company. Their materials supported bridge building and the rapid expansion of Boise in the 1890s. As with many early infrastructure ventures, electrification succeeded only after at least one false start. July 4, 1887, marked the start of electrical transmission from a plant located on the Bench. William Ridenbaugh provided expertise and manpower for the water supply and several months were spent rigging poles and lines from the Bench to the service area across the river. Additional electrical supplies allowed the building of an electric streetcar line in 1891. This ran without interruption until buses replaced the lines in 1927, tracking—and sometimes driving—the development of Boise and nearby communities. This system expanded over several decades, reaching into the North End, South Boise and across the river on Front St. A loop line, completed in 1912, ran as far as Caldwell and Nampa, providing transport throughout the valley. Three early trolley companies merged in 1912 to form the Idaho Traction Company with a depot at 7th and Bannock Streets downtown. Additional services and urban amenities arrived in the 1890s as Boise grew. Exploratory drilling for hot water was successful in 1890 and by the end of the decade many homes along Warm Springs avenue were being heated by this source. A natatorium was built in 1892 close to the source of the hot water near the Idaho State Penitentiary. Churches serving several denominations, a Jewish synagogue, a major hardware store and department store, a Masonic hall, the Columbia Theater, Saint Alphonsus' Hospital, a number of parochial and secular schools, a City Hall and a new Union Pacific passenger station, constructed when service was finally extended to downtown, were all built during the 1890s. Falk's Department Store sponsored a semi-professional baseball team representing Boise from at least 1892 and the city supported other organized sports as they became popular.

pa ( ) is the most populous city in Canyon County, Idaho, United States. The population was 100,200 at the 2020 census. It is Idaho's third-most populous city. Nampa is about 20 miles (32 km) west of Boise along Interstate 84, and 6 miles (9.7 km) west of Meridian. It is the second principal city of the Boise metropolitan area. The name "Nampa" may have come from a Shoshoni word meaning 'moccasin' or 'footprint'. According to toponymist William O. Bright, the name comes from the Shoshoni word /nampai/, meaning "foot".

History Nampa had its beginnings in the early 1880s when the Oregon Short Line Railroad built a line from Granger, Wyoming, to Huntington, Oregon, that passed through Nampa. In Nampa there is a history museum that marks the railroad's significance. More railroad lines sprang up through Nampa, making it an important railroad town. Alexander and Hannah Duffes established one of the town's first homesteads, eventually forming the Nampa Land and Improvement Company with the help of their friend and co-founder, James McGee. Despite the name, many early settlers called the town "New Jerusalem" because of its citizens' strong religious focus. After only a year the town grew from 15 homes to 50. As amenities were added, Nampa continued to grow, and it was incorporated in 1891. Downtown Nampa's street grid is oriented with the railroad tracks, which run northwest–southeast; this was done intentionally by Alexander Duffes to prevent accidents like one that occurred earlier in a town he had platted near Toronto, where a woman and her two children were killed by a train when their buggy wheel got stuck as they crossed the tracks. As the Oregon Short Line railroad originally bypassed Boise, Nampa has the fanciest of many railroad depots built in the area. Nampa gained attention in 1889 due to a purported archaeological discovery known as the Nampa figurine. George Frederick Wright wrote up details that year for the Boston Society of Natural History. The first elementary school was built in the 1890s. Lakeview School was on a hill on 6th Street and 12th Avenue North, with a view of Lake Ethel. Just after the school's centennial celebration, it was condemned as a school and sold to the First Mennonite Church. In 2008 the building was refurbished, and it is now used by the Idaho Arts Charter School. Lake Ethel, an irrigation reservoir, had long been the site of community picnics, and many citizens fished, swam, boated, and even hunted on it and its surrounding property. But the hunting didn't last long, as O. F. Persons, owner of the adjoining homestead, took offense when local hunters started shooting his pet ducks. The city later auctioned off the lake. E. H. Dewey (a former Nampa mayor) was the only bidder. But occasional flooding led to a series of lawsuits from neighbors. Dewey eventually drained Lake Ethel. Not long after, the city council became interested in buying back the Fritz Miller property as well as the Dewey home. Pressure had been building for more than four years. Nampa citizens wanted another park. On August 7, 1924, the city council passed an ordinance to purchase the Miller property and name it Lakeview Park. A bandstand was completed in 1928, and the municipal swimming pool opened on August 13, 1934. It is Nampa's largest park and many community celebrations are held there. Colonel William H. Dewey, a man who made a fortune mining in Silver City, built the Dewey Palace Hotel in 1902 for $250,000. He died in his hotel in 1903, leaving his son $1 million. The hotel survived the great fire of 1909, which burned several blocks of downtown Nampa, but was razed in 1963 after redevelopment plans failed. Relics from the hotel such as the chandelier and the hotel safe can be found at the Canyon County Historical Museum, which is in the old train depot on Front Street and Nampa City Hall. After demolition the location on First Street between 11th and 12th Ave. South was sold to private enterprise, including a bank and tire store, replacing this building with modern structures. A public-use postage stamp sized park was later placed across the street from the old palace property as a collaboration between the Downtown Alliance of Nampa (the local business council) and an Eagle Scout Project for the Boy Scouts of America. The park includes a large mural/wall sculpture of running horses commissioned for the project. A Carnegie library was built downtown in 1908; it burned down after the library moved in 1966. Nampa Public Library was then on the corner of 1st Street and 11th Avenue South in the old bank building. A new library, on 12th Avenue South, opened in 2015. Deer Flat Reservoir, an offstream irrigation storage reservoir, was constructed by the United States Bureau of Reclamation between 1906 and 1911. Known locally as Lake Lowell, it is surrounded by the Deer Flat National Wildlife Refuge, established in 1909 by President Theodore Roosevelt. The refuge is administered by the U.S. Fish and Wildlife Service. Lake Lowell is filled by the concrete New York Canal; the water is diverted from the Boise River a few miles below Lucky Peak Dam. In 1910, the Idaho State School and Hospital was built northwest of Nampa for the state's developmentally challenged population. It opened in 1918. The institution was largely self-sufficient, with a large farm staffed by the residents. The higher-functioning residents also cared for residents who could not care for themselves. The land for the farm was sold and is now golf courses (Centennial and Ridgecrest), and the residents no longer give primary care to other residents. The institution is modernized and remains in operation, though a few of the oldest buildings now house juvenile offenders. Nampa held an annual harvest festival and farmers' market from about 1908, a time of celebration and community fun. From this festival emerged the Snake River Stampede Rodeo in 1937, which continues to this day. It is one of the top 12 rodeos in the pro rodeo circuits. In 1913, a local congregation of the Church of the Nazarene built a small elementary school, which became to Northwest Nazarene College in 1915 and finally Northwest Nazarene University. As of 2025, the university has approximately 1,800 undergraduate and graduate students. Karcher Mall opened in 1965, the first enclosed shopping mall in the Treasure Valley. It was "the place to gather" for several decades until the Boise Towne Square mall was built in Boise in 1988, drawing business away. Karcher Mall was renamed District 208 in 2022. The Idaho Press-Tribune is the local newspaper for the Canyon County area.

Idaho Hispanic Community Center (IH2C) In 2003, the Hispanic Cultural Center of Idaho (HCCI) opened thanks to community support. It has recently transitioned back to the City of Nampa and was renamed the Idaho Hispanic Community Center (IH2C) and is home to the Idaho Hispanic Foundation. It hosts events, classes, and festivals, including Día de los Muertos, Hispanic Heritage Month, and Día Internacional de la Mujer. It serves as a meeting place for associations and groups. Displays of cultural history are available to the public. Nampa Train Depot Museum The Nampa Train Depot Museum is a historical depot with displays and archives of the area's railroad and cultural history. The Canyon County Historical Society saved the depot from demolition in 1972. Annual Festival of the Arts Nampa's Festival of the Arts, which began in 1987, is held in Lakeview Park every year and includes local art, music, dance, and food.

Deer Flat Middle Dike (ID #ID00277), completed 1911, 18 feet (5.5 m) high, 1,262 feet (385 m) long Deer Flat Lower Dike (ID #ID00278), completed 1908, 48 feet (15 m) high, 7,270 feet (2,220 m) long Deer Flat East Dike (ID #ID82902), completed 1911, 18 feet (5.5 m) high, 3,806 feet (1,160 m) long The reservoir it creates, Lake Lowell, has a normal surface area of 16 square miles (41 km2), and a maximum capacity of 169,000 acre-feet (208,000,000 m3). Its surface elevation is approximately 2,520 feet (770 m) above sea level. The Boise Project was among the first undertaken by the Reclamation Service after its formation in 1902. Shortly before leaving office, President Theodore Roosevelt created a national bird refuge at Deer Flat Reservoir, now Lake Lowell, with an executive order on February 25, 1909. The refuge was one of 17 federal reclamation projects referenced in the order, each of which used manmade aquifers to provide safe havens for migratory birds. The effort to include the Canyon County site was spearheaded by James H. Lowell, the president of the local Payette-Boise Water Users Association. The "globally important" Deer Flat National Wildlife Refuge for migratory fowl and other wildlife consists of two sections which contains open water, edge wetlands, grasslands and riparian and forest habitats. The largest portion of the refuge consists of Lake Lowell and its environs. The second portion comprises the Snake River islands located in non-contiguous localities along the river in Canyon, Owyhee, Payette, and Washington counties (Idaho) and Malheur and Baker counties (Oregon).

w U.S. Bureau of Reclamation), with a height of 74 feet (23 m) and a crest length of 4,165 feet (1.27 km). The Upper Embankment is the largest of a set of four dikes here impounding the water of the Boise River in offstream storage. The other dams are: Deer Flat Middle Dike (ID #ID00277), completed 1911, 18 feet (5.5 m) high, 1,262 feet (385 m) long Deer Flat Lower Dike (ID #ID00278), completed 1908, 48 feet (15 m) high, 7,270 feet (2,220 m) long Deer Flat East Dike (ID #ID82902), completed 1911, 18 feet (5.5 m) high, 3,806 feet (1,160 m) long The reservoir it creates, Lake Lowell, has a normal surface area of 16 square miles (41 km2), and a maximum capacity of 169,000 acre-feet (208,000,000 m3). Its surface elevation is approximately 2,520 feet (770 m) above sea level. The Boise Project was among the first undertaken by the Reclamation Service after its formation in 1902. Shortly before leaving office, President Theodore Roosevelt created a national bird refuge at Deer Flat Reservoir, now Lake Lowell, with an executive order on February 25, 1909. The refuge was one of 17 federal reclamation projects referenced in the order, each of which used manmade aquifers to provide safe havens for migratory birds. The effort to include the Canyon County site was spearheaded by James H. Lowell, the president of the local Payette-Boise Water Users Association. The "globally important" Deer Flat National Wildlife Refuge for migratory fowl and other wildlife consists of two sections which contains open water, edge wetlands, grasslands and riparian and forest habitats. The largest portion of the refuge consists of Lake Lowell and its environs. The second portion comprises the Snake River islands located in non-contiguous localities along the river in Canyon, Owyhee, Payette, and Washington counties (Idaho) and Malheur and Baker counties (Oregon).

tes in southwestern Idaho. Located in the Treasure Valley in Canyon County, it is directly southwest of Nampa. The earthen dam was completed 118 years ago in 1908 by the Reclamation Service (now U.S. Bureau of Reclamation), with a height of 74 feet (23 m) and a crest length of 4,165 feet (1.27 km). The Upper Embankment is the largest of a set of four dikes here impounding the water of the Boise River in offstream storage.

western United States in southwestern Idaho, near Boise and Nampa. The dams are components of the U.S. Bureau of Reclamation's Boise Project, and were designed to provide irrigation water to 500,000 acres (780 mi2; 2,000 km2) of Treasure Valley farmland in conjunction with the New York Irrigation District (New York Canal). The Boise River Diversion Dam also provides hydroelectric generation capacity.

ise Project, and were designed to provide irrigation water to 500,000 acres (780 mi2; 2,000 km2) of Treasure Valley farmland in conjunction with the New York Irrigation District (New York Canal). The Boise River Diversion Dam also provides hydroelectric generation capacity.

ver Diversion Dam also provides hydroelectric generation capacity. The dams were listed on the National Register in 1976. The three dams that make up the Diversion Dam and Deer Flat Embankments are: Boise River Diversion Dam Deer Flat Upper Embankment Deer Flat Lower Embankment See also National Register of Historic Places listings in Ada County, Idaho National Register of Historic Places listings in Canyon County, Idaho Deer Flat National Wildlife Refuge

Ada County is located in the southwestern part of Idaho, United States. As of the 2020 census, the county had a population of 494,967, which by 2025 was estimated to have risen to 546,141. Ada County is by far the state's most populous county; it is home to 26.8% of the state's population. The county seat and largest city is Boise, which is also the state capital. Ada County is included in the Boise metropolitan area. The Ada County Highway District has jurisdiction over all the local county and city streets, except for private roads and state roads.

populous county; it is home to 26.8% of the state's population. The county seat and largest city is Boise, which is also the state capital. Ada County is included in the Boise metropolitan area. The Ada County Highway District has jurisdiction over all the local county and city streets, except for private roads and state roads.

ea. The Ada County Highway District has jurisdiction over all the local county and city streets, except for private roads and state roads. In the interior Pacific Northwest east of the Cascade Range, Ada County ranks second in population, behind Spokane County, Washington. History Ada County was created by the Idaho Territory legislature on December 22, 1864, partitioned from Boise County. It is named for Ada Riggs, the daughter of H. C. Riggs, a member of the legislature; he established the county and was a co-founder of Boise.

105, which by 2025 was estimated to have risen to 275,123, making it the second-most populous county in Idaho. The county seat is Caldwell, and its largest city is Nampa. Canyon County is part of the Boise metropolitan area. History Hudson's Bay Company established Fort Boise in 1834 near what is now Parma, but abandoned it in 1855. Emigrants traveled through Canyon County on the Oregon Trail. Discovery of gold in the Boise Basin in 1862 brought settlement to the region again. The lower Boise River was fully contained within Boise County from 1863 until the formation of Ada County in 1864. Settlement of the lower Boise River west of Boise City was limited prior to the completion of the Oregon Short Line Railroad. Middleton was the first European settlement of Canyon County, starting in 1863. The 1870 Census for Ada County listed 76 residents of the Boise Valley, excluding Boise City and the 1880 Census listed 44 residents at Middleton. The arrival of the railroad at Caldwell led to the establishment of a town there as of August 1883. Businessmen James A. McGee and Alexander Duffes filed the plat for nearby Nampa in 1886. Parma was settled around the same time, with the Old Fort Boise post office being moved to the town's location; it was incorporated in 1904. Ada County established precincts for each of the settlements with a combined 1890 Census population of 2,311. Significant settlement of Greenleaf and Notus started around 1904 with the two settlements listed as precincts at the 1910 census. Notus was incorporated in 1921 while Greenleaf was incorporated prior to 1980. Melba was incorporated in 1912 while Wilder was incorporated in 1919. The City of Star annexed a portion of territory in northeast Canyon County prior to 2007, becoming the county's ninth incorporated city. The majority of Star is located within Ada County. The Idaho Legislature created Canyon County from Ada County in an act approved March 7, 1891, effective at the November 26, 1892, election. Caldwell was established as the county seat. The county originally contained all of Canyon and Payette counties and part of Gem; Gem County formed in 1915 and Payette County in 1917.

History Hudson's Bay Company established Fort Boise in 1834 near what is now Parma, but abandoned it in 1855. Emigrants traveled through Canyon County on the Oregon Trail. Discovery of gold in the Boise Basin in 1862 brought settlement to the region again. The lower Boise River was fully contained within Boise County from 1863 until the formation of Ada County in 1864. Settlement of the lower Boise River west of Boise City was limited prior to the completion of the Oregon Short Line Railroad. Middleton was the first European settlement of Canyon County, starting in 1863. The 1870 Census for Ada County listed 76 residents of the Boise Valley, excluding Boise City and the 1880 Census listed 44 residents at Middleton. The arrival of the railroad at Caldwell led to the establishment of a town there as of August 1883. Businessmen James A. McGee and Alexander Duffes filed the plat for nearby Nampa in 1886. Parma was settled around the same time, with the Old Fort Boise post office being moved to the town's location; it was incorporated in 1904. Ada County established precincts for each of the settlements with a combined 1890 Census population of 2,311. Significant settlement of Greenleaf and Notus started around 1904 with the two settlements listed as precincts at the 1910 census. Notus was incorporated in 1921 while Greenleaf was incorporated prior to 1980. Melba was incorporated in 1912 while Wilder was incorporated in 1919. The City of Star annexed a portion of territory in northeast Canyon County prior to 2007, becoming the county's ninth incorporated city. The majority of Star is located within Ada County. The Idaho Legislature created Canyon County from Ada County in an act approved March 7, 1891, effective at the November 26, 1892, election. Caldwell was established as the county seat. The county originally contained all of Canyon and Payette counties and part of Gem; Gem County formed in 1915 and Payette County in 1917.

2000 census As of the 2000 census, there were 131,441 people, 45,018 households and 33,943 families living in the county. The population density was 223 people per square mile (86 people/km2). There were 47,965 housing units at an average density of 81 units per square mile (31 units/km2). The racial makeup of the county was 83.10% White, 0.32% Black or African American, 0.85% Native American, 0.80% Asian, 0.13% Pacific Islander, 12.17% from other races, and 2.62% from two or more races. Hispanic or Latino of any race were 18.61% of the population. 15.9% were of German, 12.7% English, 10.3% American and 7.6% Irish ancestry. There were 45,018 households, of which 39.80% had children under the age of 18 living with them, 60.70% were married couples living together, 10.10% had a female householder with no husband present, and 24.60% were non-families. 19.80% of all households were made up of individuals, and 8.40% had someone living alone who was 65 years of age or older. The average household size was 2.85 and the average family size was 3.28. 30.90% of the population were under the age of 18, 10.70% from 18 to 24, 28.30% from 25 to 44, 19.10% from 45 to 64, and 11.00% who were 65 years of age or older. The median age was 30 years. For every 100 females, there were 98.70 males. For every 100 females age 18 and over, there were 96.30 males. The median household income was $35,884 and the median family income was $40,377. Males had a median income of $29,418 compared with $22,044 for females. The per capita income for the county was $15,155. About 8.70% of families and 12.00% of the population were below the poverty line, including 14.50% of those under age 18 and 10.70% of those age 65 or over. Communities Cities Unincorporated communities Bowmont Huston Roswell Sunnyslope Walters Ferry, Idaho Politics Like the majority of Idaho, Canyon County is reliably Republican by comfortable margins. The last time a Democratic candidate carried the county was in 1936 by Franklin D. Roosevelt.

city in Idaho. As of the 2020 census, Caldwell had a population of 59,996. Caldwell is considered part of the Boise metropolitan area, and is the location of the College of Idaho. The city is located approximately 24 miles (39 km) west of Boise, and approximately 17 miles (27 km) east of the Oregon border. History The present-day location of Caldwell is along a natural passageway to the Inland and Pacific Northwest. Native American tribes from the west coast, north Idaho and as far away as Colorado came to the banks of the Boise River for annual trading fairs, or rendezvous. European and some Hawaiian explorers and traders soon followed the paths left by Native Americans and hopeful emigrants later forged the Oregon Trail and followed those paths to seek a better life in the Oregon Territory. Pioneers of the Trail traveled along the Boise River to Canyon Hill and forded the river close to the Silver Bridge on Plymouth Street. During the Civil War, the discovery of gold in Idaho's mountains brought a variety of new settlers into the area. Many never made it to the mines but settled along the Boise River and run ferries, stage stations, and freighting businesses. These early entrepreneurs created small ranches and farms in the river valleys. Caldwell's inception occurred largely as a result of the construction of the Oregon Short Line Railroad, which connected Wyoming to Oregon through Idaho. Robert E. Strahorn came to the Boise River Valley in 1883 to select a route for the railroad. He rejected the grade into Boise City as too steep and chose a site 30 miles to the west. He drove a stake into an alkali flat of sagebrush and greasewood and the City of Caldwell was platted. Caldwell was named after one of Strahorn's business partners, Alexander Caldwell, a former senator from Kansas. When Caldwell was platted in August 1883, its founder, the Idaho and Oregon Land Improvement Company, started persuading settlers and businessmen to move to the area. Within four months, Caldwell had 600 residents living in 150 dwellings, 40 businesses, a school, a telephone exchange, and two newspapers. On January 15, 1890, the Board of Commissioners of Ada County issued a handwritten order incorporating the City of Caldwell. The College of Idaho was founded in Caldwell in 1891. In 1892, Canyon County was established from a portion of Ada County, and Caldwell was named the county seat. Irrigation canals and waterways were constructed throughout Canyon County, providing the foundation for an agricultural economy. The Oregon Short Line Railroad became part of the larger Union Pacific Railroad network and in 1906 the Caldwell freight and passenger depot was constructed. Caldwell experienced moderate growth as an agricultural processing, commercial retail and educational center during the 20th century. In 2009, the City of Caldwell completed a revitalization project to restore Indian Creek, which runs through downtown Caldwell, but had been used for sewage disposal by local industries and been covered over.

History The present-day location of Caldwell is along a natural passageway to the Inland and Pacific Northwest. Native American tribes from the west coast, north Idaho and as far away as Colorado came to the banks of the Boise River for annual trading fairs, or rendezvous. European and some Hawaiian explorers and traders soon followed the paths left by Native Americans and hopeful emigrants later forged the Oregon Trail and followed those paths to seek a better life in the Oregon Territory. Pioneers of the Trail traveled along the Boise River to Canyon Hill and forded the river close to the Silver Bridge on Plymouth Street. During the Civil War, the discovery of gold in Idaho's mountains brought a variety of new settlers into the area. Many never made it to the mines but settled along the Boise River and run ferries, stage stations, and freighting businesses. These early entrepreneurs created small ranches and farms in the river valleys. Caldwell's inception occurred largely as a result of the construction of the Oregon Short Line Railroad, which connected Wyoming to Oregon through Idaho. Robert E. Strahorn came to the Boise River Valley in 1883 to select a route for the railroad. He rejected the grade into Boise City as too steep and chose a site 30 miles to the west. He drove a stake into an alkali flat of sagebrush and greasewood and the City of Caldwell was platted. Caldwell was named after one of Strahorn's business partners, Alexander Caldwell, a former senator from Kansas. When Caldwell was platted in August 1883, its founder, the Idaho and Oregon Land Improvement Company, started persuading settlers and businessmen to move to the area. Within four months, Caldwell had 600 residents living in 150 dwellings, 40 businesses, a school, a telephone exchange, and two newspapers. On January 15, 1890, the Board of Commissioners of Ada County issued a handwritten order incorporating the City of Caldwell. The College of Idaho was founded in Caldwell in 1891. In 1892, Canyon County was established from a portion of Ada County, and Caldwell was named the county seat. Irrigation canals and waterways were constructed throughout Canyon County, providing the foundation for an agricultural economy. The Oregon Short Line Railroad became part of the larger Union Pacific Railroad network and in 1906 the Caldwell freight and passenger depot was constructed. Caldwell experienced moderate growth as an agricultural processing, commercial retail and educational center during the 20th century. In 2009, the City of Caldwell completed a revitalization project to restore Indian Creek, which runs through downtown Caldwell, but had been used for sewage disposal by local industries and been covered over.

location of the College of Idaho. The city is located approximately 24 miles (39 km) west of Boise, and approximately 17 miles (27 km) east of the Oregon border. History The present-day location of Caldwell is along a natural passageway to the Inland and Pacific Northwest. Native American tribes from the west coast, north Idaho and as far away as Colorado came to the banks of the Boise River for annual trading fairs, or rendezvous. European and some Hawaiian explorers and traders soon followed the paths left by Native Americans and hopeful emigrants later forged the Oregon Trail and followed those paths to seek a better life in the Oregon Territory. Pioneers of the Trail traveled along the Boise River to Canyon Hill and forded the river close to the Silver Bridge on Plymouth Street. During the Civil War, the discovery of gold in Idaho's mountains brought a variety of new settlers into the area. Many never made it to the mines but settled along the Boise River and run ferries, stage stations, and freighting businesses. These early entrepreneurs created small ranches and farms in the river valleys. Caldwell's inception occurred largely as a result of the construction of the Oregon Short Line Railroad, which connected Wyoming to Oregon through Idaho. Robert E. Strahorn came to the Boise River Valley in 1883 to select a route for the railroad. He rejected the grade into Boise City as too steep and chose a site 30 miles to the west. He drove a stake into an alkali flat of sagebrush and greasewood and the City of Caldwell was platted. Caldwell was named after one of Strahorn's business partners, Alexander Caldwell, a former senator from Kansas. When Caldwell was platted in August 1883, its founder, the Idaho and Oregon Land Improvement Company, started persuading settlers and businessmen to move to the area. Within four months, Caldwell had 600 residents living in 150 dwellings, 40 businesses, a school, a telephone exchange, and two newspapers. On January 15, 1890, the Board of Commissioners of Ada County issued a handwritten order incorporating the City of Caldwell. The College of Idaho was founded in Caldwell in 1891. In 1892, Canyon County was established from a portion of Ada County, and Caldwell was named the county seat. Irrigation canals and waterways were constructed throughout Canyon County, providing the foundation for an agricultural economy. The Oregon Short Line Railroad became part of the larger Union Pacific Railroad network and in 1906 the Caldwell freight and passenger depot was constructed. Caldwell experienced moderate growth as an agricultural processing, commercial retail and educational center during the 20th century. In 2009, the City of Caldwell completed a revitalization project to restore Indian Creek, which runs through downtown Caldwell, but had been used for sewage disposal by local industries and been covered over.

Meridian is a city located in Ada County, Idaho, United States. The population was 117,635 at the 2020 census, making it the second most populous city in the county and Idaho, after Boise, the state capital.

Rail transportation (1908–28) Following the raising of $4,000 to lay the Interurban rail line from Onweiler (Meridian and Ustick Roads), the tracks were completed into the village center. Turning east on Broadway and ending at East Second, the last car would spend the night in Meridian before returning to Boise early the next morning with passengers and freight. The interurban Station and Generator building (west one-third of the old library at Meridian and Idaho Streets) was built in 1912, and the line continued on to Nampa via Meridian. The tracks down Broadway were not used after 1912. The Interurban Company entered into receivership and closed in 1928 after 20 years of providing continuous transportation to neighboring towns. It was Meridian's main connection to the area outside the local community. The Union Pacific Railroad spur opened in 1900 and is currently operated by the Boise Valley Railroad. Many industrial customers continue to ship forest, agricultural, and chemical products along this corridor. Creamery (1929–70) The city's official website describes the history of the Ada County Dairymen's cooperative creamery as follows:The lowest days of the Great Depression brightened for area dairymen when the Ada County Dairymen's cooperative creamery began operation in 1929. It provided milk checks to those who were members of the cooperative, enabling them to pay their taxes and provide food for their families. Other community members hauled milk to the creamery and were employed by the creamery, whose product was Challenge Butter. The creamery ran seven days a week for 40 years. Additions and improvements were made while the plant was in full operation. Later years saw the Wyeth Laboratories affiliate with the creamery to manufacture SMA baby formula.

Creamery (1929–70) The city's official website describes the history of the Ada County Dairymen's cooperative creamery as follows:The lowest days of the Great Depression brightened for area dairymen when the Ada County Dairymen's cooperative creamery began operation in 1929. It provided milk checks to those who were members of the cooperative, enabling them to pay their taxes and provide food for their families. Other community members hauled milk to the creamery and were employed by the creamery, whose product was Challenge Butter. The creamery ran seven days a week for 40 years. Additions and improvements were made while the plant was in full operation. Later years saw the Wyeth Laboratories affiliate with the creamery to manufacture SMA baby formula.