Bureau of Reclamation Banner
Shoshone Project
Photo of Buffalo Bill Powerplant
Project Links
Project History
Project Data
Contact Information
Related Facilities
Related Documents
Shoshone Project History (74 KB) (pdf)
General Description| Plan| Development| Benefits
General Description

The Shoshone Project is near Cody in northwestern Wyoming. Features of the project include Buffalo Bill Dam and Reservoir, Shoshone and . Heart Mountain Powerplants, associated transmission facilities, and a network of canals and laterals to deliver water to the project lands. A full irrigation water supply is available for 93,113 acres. Supplemental service is provided for 14,561 acres.

Return to top


Floodwaters of the Shoshone River are stored in Buffalo Bill Reservoir for later release for irrigation and power generation. The project comprises four irrigation divisions: Garland Division, with 35,863 irrigable acres; Frannie Division, 14,600; Willwood Division, 11,530; and Heart Mountain Division, 31,120.

Power is developed at the Shoshone and Heart Mountain Powerplants. The system is interconnected with the West Division of the Pick-Sloan Missouri Basin Program. Transmission lines, under the Department of Energy, consist of 117.7 miles of 69-kilovolt and 14.0 miles of 34.5-kilovolt lines. The Shoshone Canyon Conduit, beginning at Buffalo Bill Dam, conveys water to the Heart Mountain Powerplant. Irrigation releases then cross the river through an inverted siphon into the Heart Mountain Canal for the Heart Mountain Division. Water for the Garland Division is diverted from the Shoshone River into the Garland Canal at Corbett Diversion Dam. The Frannie Canal serves the Frannie Division from the Garland Canal. Water for the Willwood Division is diverted into the Willwood Canal at Willwood Diversion Dam.

Facility Descriptions

Buffalo Bill Dam, on the Shoshone River about 6 miles upstream from Cody, Wyoming, is a concrete arch structure of constant radius. The structural height is 325 feet and the volume is 82,900 cubic yards. This was one of the first high concrete dams built in the United States. The reservoir impounds 423,970 acre-feet of water. Shoshone Powerplant is near the base of Buffalo Bill Dam and originally had a capacity of 6,012 kilowatts. Because of maintenance and safety problems, the powerplant was removed from service in March 1980. A new 3-megawatt unit was placed in service in 1991 (see Shoshone Powerplant history section in this website) as a portion of the Buffalo Bill Unit of the Pick-Sloan Missouri Basin Program.

The Heart Mountain Powerplant is at the outlet of Shoshone Canyon Conduit about 4 miles southwest of Cody, Wyoming. The capacity of the plant is 5,000 kilowatts.

Heart Mountain Irrigation System

The 26-mile-long Heart Mountain Canal begins at the outlet to Shoshone River Siphon, which spans the river below the Shoshone Canyon Conduit outlet. The initial capacity of the canal is 915 cubic feet per second. The siphon is part steel and part concrete, 1,640 feet long, and 10.25 feet in diameter.

Garland and Frannie Irrigation Systems

Corbett Diversion Dam is a reinforced concrete flat-slab and buttress weir with a short embankment wing. It is on the Shoshone River about 16 miles downstream from Buffalo Bill Dam. The hydraulic height is 12 feet. The outlet works is a concrete-lined horseshoe tunnel about 11 feet in diameter and 17,355 feet long.

The Garland Canal supplies the Garland and Frannie Divisions through the Frannie and Deaver Canals. Garland Canal begins at Corbett Diversion Dam and extends northeast about 18 miles. Its initial capacity is 1,000 cubic feet per second. Frannie Canal begins at the Garland Canal and is 44 miles long. The initial capacity is 550 cubic feet per second. Deaver Canal begins at the Frannie Canal. It is 24 miles long and has an initial capacity of 194 cubic feet per second.

Offstream storage of municipal water is provided by Deaver Reservoir. This reservoir is in the Frannie Division and has a capacity of 681 acre-feet. Ralston Reservoir on the Garland Canal is no longer used as an operational storage reservoir. It provides an emergency waste route during storms, and collects drainage water.

Willwood Diversion Dam, on the Shoshone River about 8 miles downstream from Corbett Dam, is a concrete gravity structure with a hydraulic height of 41 feet. Willwood Canal begins at the diversion dam. The canal is about 28 miles long and the diversion capacity is 320 cubic feet per second

Operating Agencies

The irrigation system for the Frannie Division is operated by the Deaver Irrigation District, the Garland Division by the Shoshone Irrigation District, the Willwood Division by the Willwood Irrigation District, and the Heart Mountain Division by the Heart Mountain Irrigation District. Buffalo Bill Dam and the powerplant are operated by the Bureau of Reclamation. The transmission system is operated by the Department of Energy.

Return to top



Col. William F. `Buffalo Bill` Cody made the area now occupied by the Shoshone Project famous in the early days of the West. Buffalo Bill and his companions were the first to perceive the possibilities of turning the sagebrush flats of Wyoming`s Bighorn Basin into a land of agricultural abundance through irrigation. In 1899, they acquired from the State of Wyoming, a right to appropriate waters from the Shoshone River for the irrigation of about 60,000 acres of public domain near Cody. As an initial step, they constructed a canal on the south side of the Shoshone River. In 1903, the Wyoming State Board of Land Commissioners, with Cody`s approval, urged the Reclamation Service to complete the proposed irrigation development.


Reclamation Service engineers investigated the proposed project and, to obtain the maximum benefit from the flow of the river, recommended construction of a dam or the Shoshone River at the upstream end of the sheer-walled canyon 7 miles west of Cody, Wyoming.


The project was authorized by the Secretary of the Interior on February 10, 1904, under authority of the Reclamation Act of June 17, 1902. Heart Mountain power development was found feasible and authorized by the Secretary on June 19, 1945, under the provisions of the Reclamation Project Act of 1939.


Construction began in early 1904. Ralston Dam and Corbett Dam were completed in 1908, making the first water available for irrigation. Buffalo Bill Dam began storing water in 1910. Deaver Dam was completed in 1918, and the Willwood Dam in 1924. The first lands open to settlement in the project were in the Garland Division in the vicinity of Powell, Wyoming. Development of the Garland Division was virtually complete in 1918. Between 1917 and 1920, the Frannie Division, comprising lands principally between the towns of Frannie and Cowley, Wyoming, was opened. The Willwood Division, lying south of the Shoshone River between Willwood Dam and Penrose, Wyoming, was settled under successive openings between 1927 and 1938. The Heart Mountain Division, completed in 1947, extends along the north side of the Shoshone River from the vicinity of Cody, Wyoming, to a point about 7 miles northwest of Ralston, Wyoming.

Rehabilitation and Betterment (R&B) Program

The Shoshone Irrigation District, Garland Division, entered into a repayment contract with the United States on March 21, 1969, to repay the cost of the R&B Program. Construction work included lining of laterals with concrete or other materials; placing of canals, laterals, and drains in pipe; and replacement of minor structures. The R&B Program, authorized un the 1969 contract, was completed in 1982. Several other R&B contracts with the various divisions of the Shoshone Project have been initiated and completed. The current R&B contract was entered into in 1992 with the Shosone Irrigation Project Joint Powers Board representing all four divisions of the Shoshone Project. Work under the current contract is scheduled to be completed in 2000.

Return to top



Principal crops grown are beans, alfalfa, pasture, oats, corn, barley, and sugar beets. As these are largely feed crops, the project assists materially in stabilizing the livestock industry in the area.


Buffalo Bill Dam and Reservoir are located in a rugged scenic canyon adjacent to a main highway which leads into Yellowstone National Park. The reservoir area provides camping, picnicking, swimming, boating, and good fishing for rainbow, brown, and Mackinaw trout. Winter fishing is popular.

For specific information about any of these recreation sites, user the menu above (Related Facilities) to navigate to the specific dam or reservoir.

Hydroelectric Power

Power produced on the project is fed into a grid system which serves an area extending into three States.

Flood Control

Buffalo Bill Reservoir provides incidental flood control on the Shoshone River. Although there is no specific reservoir capacity assigned for flood control, the Shoshone Project has provided an accumulated $9,003,000 in flood control benefits from 1950 to 1999.

Return to top

Last updated: Apr 05, 2013