Buffalo Bill Dam is a concrete arch-gravity dam on the

Shoshone River The Shoshone River is a long river in northern Wyoming, United States. Its headwaters are in the Absaroka Range in Shoshone National Forest. It ends when it runs into the Big Horn River near Lovell, Wyoming. Cities it runs near or through ...

in the

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Wyoming Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...

. Originally , it was the tallest dam in the world when it opened in 1910; a extension was added in 1992 in one of numerous changes and improvements to the structure and its support facilities, which include two full time power generators and two seasonal operations added between 1920 and 1994, and a irrigation tunnel completed in 1939. The dam is located in Shoshone Canyon, and named after the famous

Wild West The American frontier, also known as the Old West, and popularly known as the Wild West, encompasses the geography, history, folklore, and culture associated with the forward wave of American expansion in mainland North America that bega ...

figure William "Buffalo Bill" Cody, who founded the nearby town of Cody and owned much of the land now covered by the reservoir formed by its construction. It is part of the Shoshone Project, successor to several visionary schemes promoted by Cody to irrigate the

Bighorn Basin The Bighorn Basin is a plateau region and intermontane basin, approximately 100 miles (160 km) wide, in north-central Wyoming in the United States. It is bounded by the Absaroka Range on the west, the Pryor Mountains on the north, the Bigho ...

and turn it from a semi-arid sagebrush-covered plain to productive agricultural land. Known at the time of its construction as Shoshone Dam, it was renamed in 1946 to honor Cody. The original structure was designed by engineer Daniel Webster Cole and built between 1905 and 1910. It was listed on the

National Register of Historic Places The National Register of Historic Places (NRHP) is the Federal government of the United States, United States federal government's official United States National Register of Historic Places listings, list of sites, buildings, structures, Hist ...

in 1971 and named a

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by the

American Society of Civil Engineers The American Society of Civil Engineers (ASCE) is a tax-exempt professional body founded in 1852 to represent members of the civil engineering profession worldwide. Headquartered in Reston, Virginia, it is the oldest national engineering soci ...

in 1973. The land around the reservoir is maintained as Buffalo Bill State Park.

Description

The dam is a concrete arch-gravity dam, wide at the base and wide at the crest, with an original height of , extended between 1985 and 1992. The concrete structure measures deep at the base, tapering to at the crest, with a volume of of concrete. It is anchored into

Pre-Cambrian The Precambrian ( ; or pre-Cambrian, sometimes abbreviated pC, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the ...

granitic A granitoid is a broad term referring to a diverse group of coarse-grained igneous rocks that are widely distributed across the globe, covering a significant portion of the Earth's exposed surface and constituting a large part of the continental ...

rock on either side. The spillway is an uncontrolled overflow weir on the south side, wide, dropping through a tunnel in the south abutment. The first of four full-time and seasonal power generation facilities was added in 1922. * Originally equipped with two generators, the Shoshone Power Plant was expanded to a third in 1931, with a total capacity of 6 MW. All three were decommissioned in 1980, and a single 3 MW generator was put on line in 1992. * The Heart Mountain Power Plant was built in 1947, then upgraded with a new seasonally operated 5 MW turbine concurrently with the dam heightening project. * The Buffalo Bill Power Plant was built concurrently with the dam heightening project and opened with three 6 MW generators in 1992. * The Spirit Mountain Power Plant was opened in 1994, and seasonally operates a 4.5 MW generator. The Heart Mountain Canal Project, which brings water to irrigate lands to the north of the river, required the construction of the Shoshone Canyon Tunnel, completed in 1939.

Construction

With the authorization of the Shoshone Project in 1904, Buffalo Bill Dam became one of the earliest projects of the new

Bureau of Reclamation The Bureau of Reclamation, formerly the United States Reclamation Service, is a List of United States federal agencies, federal agency under the U.S. Department of the Interior, which oversees water resource management, specifically as it ...

. The ambitious project involved the construction of one of the first high concrete dams in the United States. Work began immediately, with drilling for geologic investigation starting in July 1904 and continuing for ten months. Work proceeded concurrently on the construction of an access road up the narrow canyon from Cody. The chosen contractor, Prendergast & Clarkson of Chicago, started work in September 1905, building a camp for workers and starting on a diversion dam, which was to divert the river into a wooden

flume A flume is a human-made channel for water, in the form of an open declined gravity chute whose walls are raised above the surrounding terrain, in contrast to a trench or ditch. Flumes are not to be confused with aqueducts, which are built to t ...

, through a tunnel and out through another flume to rejoin the river bed. Two men were killed in the construction of the tunnel. A June 1906 flood destroyed the flume. The delay caused the Bureau of Reclamation to suspend the contractor's contract and to call upon the contractor's bonding company, the U.S. Fidelity and Guaranty Company, to ensure the completion of the work. Little work was done until March 1907. Another flood in July damaged the diversion dam again. Working conditions were harsh, leading to the first strike in Wyoming's history in November, in which workers demanded and received three dollars a day from USF&G. USF&G delegated responsibility for the work to two new contractors, Locher and Grant Smith and Company, in March 1908. Work progressed more quickly, with the first concrete pours in April. Spring floods set the project back once again, causing concrete work to be suspended. Concrete work started again in March 1909, and despite more spring flooding that suspended work from July to September, work moved quickly. Another threatened strike was broken when Italian laborers were replaced with Bulgarian workers. Final concrete was poured in January 1910, with a final cost of $1.4 million. Seven construction workers were killed on the project. Immediately after completion the dam suffered from leakage through the outlet works, leading to low water elevations that exposed mudflats, which soon produced dense blowing dust. Corrective work to valves took until 1915. Problems with the north abutment's outlet works (on the right, facing the dam from downstream) led to their abandonment in 1959. They were sealed in 1961. The reservoir began to lose capacity immediately as a result of the Shoshone's heavy silt load, and the material deposited at the head of the reservoir continued to blow when the reservoir was drawn down. Work continued on silt dikes and reforestation into the 1950s, but capacity is reduced from the reservoir's nominal capacity of to due to siltation. The new reservoir covered hot springs at the forks of the Shoshone, similar to those found at

Colter's Hell Colter's Hell is an area of fumaroles and hot springs on the Shoshone River near Cody in the U.S. state of Wyoming. The thermal area covers about at the mouth of the Shoshone's canyon. Its thermal activity has declined since its description b ...

at the mouth of the Shoshone Canyon.

Shoshone Power Plant

Work on the Shoshone Power Plant started in 1920. The power plant is located downstream from the dam on the north side of the canyon. Following delays for spring flooding, work on the power house and supply tunnel was complete in 1922, ready for the installation of electrical equipment. Generating units 1 and 2 came on line in 1922, with Unit 3 in 1931. Installed capacity was 6.012 MW. All three units were shut down in 1980, worn out from fifty years of service. 1 and 2 were decommissioned and left in place, while 3 was replaced with a new 3 MW

Francis turbine The Francis turbine is a type of water turbine. It is an inward-flow reaction turbine that combines radial and axial flow concepts. Francis turbines are the most common water turbine in use today, and can achieve over 95% efficiency. The pro ...

unit that started operation in 1992. The plant operates with a head of .

Shoshone Canyon Tunnel

The proposed Heart Mountain Canal project, intended to irrigate lands to the north of the river, required a new tunnel to direct irrigation waters to a suitable elevation for distribution. Work on the Shoshone Canyon Tunnel started in 1937, accompanied by the death of two tunnel workers who were overcome by fumes from explosives and

hydrogen sulfide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is toxic, corrosive, and flammable. Trace amounts in ambient atmosphere have a characteristic foul odor of rotten eggs. Swedish chemist ...

from nearby geothermal activity, and were subsequently struck by construction equipment. A natural cave had to be crossed by a concrete flume of two spans, constructed under difficult conditions in a high-gas environment. Work on the tunnel by the Utah Construction Company was complete in 1939.

Heart Mountain Power Plant

The Heart Mountain Powerplant was built at the tunnel's outlet in 1947 as a temporary facility. It was rebuilt concurrently with the dam heightening project and is operated on a seasonal basis. It operates a 5 MW Francis turbine on a head.

Renovation and height increase

Starting in 1985, the crest of the dam was raised , increasing the reservoir's capacity by when the project was completed in 1993. The spillways were enlarged and equipped with radial arm gates. The project also included a visitor center, located at the north end of the dam's crest. The additional height allowed 25.5 MW of additional generating capacity to be added to the project. The expanded reservoir inundated facilities at Buffalo Bill State Park, requiring their relocation and reconstruction.

Buffalo Bill Power Plant

The Buffalo Bill Power Plant was built concurrently with the work to increase the dam's height in 1992. The plant, located in Shoshone Canyon downstream from the original Shoshone Powerplant, operates three Francis turbines with generators rated at 6 MW each on a head of .

Spirit Mountain Power Plant

The Spirit Mountain Powerplant receives pressurized water through a conduit. It primarily functions to dissipate the pressure in the conduit before it enters an open canal, generating power as a byproduct. The unit operates a Francis turbine generating 4.5 MW on a seasonal base load basis, with a head. It was built in 1994.

References

External links

Buffalo Bill Dam
at the U.S. Bureau of Reclamation
Shoshone Project
at the U.S. Bureau of Reclamation
Buffalo Bill Dam Visitor CenterBuffalo Bill State ParkBuffalo Bill Dam
at the Wyoming State Historic Preservation Office
Buffalo Bill Dam Construction Photographs
at the

University of Wyoming The University of Wyoming (UW) is a Public university, public land-grant university, land-grant research university in Laramie, Wyoming, United States. It was founded in March 1886, four years before the territory was admitted as the 44th state, ...

–

American Heritage Center The American Heritage Center is the University of Wyoming's repository of manuscripts, rare books, and the university archives. Its collections focus on Wyoming and the Rocky Mountain West (including politics, settlement, Native Americans, and W ...

*
Buffalo Bill Dam video tour

Buffalo Bill Dam Construction Photograph Album
at the

{{Authority control Arch–gravity dams Buildings and structures in Park County, Wyoming Dams completed in 1910 Dams in Wyoming Dams on the National Register of Historic Places in Wyoming Energy infrastructure completed in 1931 Historic American Engineering Record in Wyoming Historic Civil Engineering Landmarks Hydroelectric power plants in Wyoming Landforms of Park County, Wyoming National Register of Historic Places in Park County, Wyoming Reservoirs in Wyoming United States Bureau of Reclamation dams