The concrete arch dam at Pelton dates from 1958, has a height of 204 feet (62 m) from bedrock, a width of 965 feet (294 m) at its crest, and generates 110 megawatts of electricity.[1]
Upstream, to the south, Pelton Dam impounds the waters of the Deschutes to create the deep Lake Simtustus in a relatively narrow canyon about 7 miles (11 km) back to the 1964 Round Butte Dam. The lake has a surface area of about 540 acres (220 ha) and holds 33,190 acre-feet (40,940,000 m3) of water. The name "Simtustus" honors a native who scouted for the U.S. Army during the 1867–68 campaign against the Paiutes.[2]
Downstream, 2.5 miles (4 km) north, a regulating dam controls the river flow. The area between is called the Pelton Regulating Reservoir. In 1982 the Confederated Tribes of Warm Springs installed a hydroelectric turbine unit in the regulating dam for additional power.[3] Between 2000 and 2005 the CTWS also asserted itself as a stakeholder in the project's re-licensing negotiations between Portland General Electric and the Federal Energy Regulatory Commission, winning key environmental, cultural, and water rights concessions.[4]
On June 29, 2021, Pelton Dam recorded a temperature of 119°F (48.3°C), making it the third time Oregon’s highest temperature was recorded. Prineville recorded a temperature of 119°F on July 28, 1898, and Pendleton recorded the same temperature shortly after on August 10 that same year.
