American Falls Water, Power & Light Company, Island Power Plant, Snake River, below American Falls Dam, American Falls, Power County, ID

Significance: This site represents technology associated with the first era of long distance electric power transmission in the state. It is also a representative example of an early low-head hydroelectric power plant built in the American West. / Originally built by the American Falls Power, Water and Light Company in 1901-1902, the Island Plant at American Falls played an important role in the development of Pocatello, Idaho. Erected under the organizational leadership of James Brady, an entrepreneur involved in the early commercial development of the upper Snake River Valley, the Island Plant was an interesting low-head hydroelectric plant that, though not a "pioneer" in western electric power technology, was a good representative example of this type of generating facility. First operated in July 1902, it was removed from service in 1927 following completion of the American Falls Dam by the Bureau of Reclamation. At the time of recording in 1976 the plant was devoid of original equipment except for its two horizontal double-runner Samson turbines made by James Leffel and Co. of Springfield Ohio. These turbines were rated at 1000 horsepower under a 36 foot head and were direct coupled to a General Electric Co. 500 kw, 3-phase AC generator. Turbine control was achieved by a Type B Lombard governor belted to the main shaft which regulated the amount of water entering the turbine wicket gates in proportion to the demand for electric power. A bank of three 250 kw oil insulated, water cooled transformers reportedly raised the voltage from 2300 volts to 33,500 before transmission to Pocatello, approximately 25 miles away.
Unprocessed Field note material exists for this structure: FN-1
Survey number: HAER ID-2
Building/structure dates: 1902 Initial Construction