From Feed Line No. 8

THE SNOQUALMIE FALLS POWER PLANT
An 1898 Milestone in Electric Power Generation

It was Nikola Tesla's AC power system, first used commercially in 1895, that made possible the harnessing of often remote waterfalls and the long distances transmission of their power to metropolitan centers.  By early 1897 there were some 300 electrical power generating plants operating here in the United States. The most important of these, the Adams Hydro-Electric Power Station, had transmitted 746 kilowatts of AC power 26 miles from Niagara Falls to Buffalo, New York on Nov. 16, 1896.  The plant's generators were housed in an above-ground structure positioned just above the falls on the north shore of the Niagara River.

Washington state's 100+ year old Snoqualmie Falls power plant was the first ever to house its generators completely below ground. The underground cavity, which initially held four horizontal impulse type waterwheel turbines and four stationary field 3-phase Westinghouse generators, was carved out of solid bedrock 270 feet below the surface.  Locating a generating station in this manner represented an entirely new mode of construction as America transitioned into the present era of electric power.