From Washington to you
Bonneville Dam
Bonneville Dam · Skamania County · first powerhouse completed 1938
The first federal lock and dam on the Columbia and Snake spans the river between Oregon and Washington at river mile 146.1.
Bonneville Lock and Dam crosses the Columbia River between Oregon and Washington at river mile 146.1. The Corps of Engineers lists the official location as Cascade Locks, Oregon. The project spans the river; this pin sits on the Washington shore.
Congress authorized the dam in the 1935 Rivers and Harbors Act. The first powerhouse, spillway, and lock were completed in 1938. The second powerhouse opened in 1981, and the lock was expanded in 1993. The project was listed on the National Register of Historic Places in 1986 and declared a National Historic Landmark in 1987. The Corps calls it the first federal lock and dam on the Columbia and Snake.
The dam is 171 feet high and 2,477 feet long. Powerhouse 1 has 10 units and 518 megawatts. Powerhouse 2 has 8 units and 532 megawatts. Eighteen turbines produce more than 1,200 megawatts, enough for about 900,000 homes. The source below is the Corps Northwestern Division fact sheet.
- Geography & Geology
- History
Sources (1)
government · Tier S
U.S. Army Corps of EngineersBonneville Dam and Lake Bonneville
Last reviewed: September 20, 2026
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