Bonneville Lock and Dam consists of several run-of-the-river hydroelectric dam structures that together complete a span of the Columbia River between the U.S. states of Oregon and Washington at River Mile 146.1. The dam is located 40 miles (64 km) east of Portland, Oregon, in the Columbia River Gorge. The primary functions of Bonneville Lock and Dam are electrical power generation and river navigation. The dam was built and is managed by the United States Army Corps of Engineers. Electrical power generated at Bonneville is distributed by the Bonneville Power Administration. Bonneville Lock and Dam is named for Army Capt. Benjamin Bonneville, an early explorer credited with charting much of the Oregon Trail. The Bonneville Dam Historic District was designated a National Historic Landmark District in 1987.

Dimensions and statistics of Bonneville Lock and dam:
  • Owner: U.S. Army Corps of Engineers, Portland District
  • Location: On Columbia River about 40 miles upstream from Portland, Oregon
  • First Powerhouse – Constructed in 1933-37; Dam 313 m (1,027 ft) long x 77 feet (23 m) high forebay; 10 generators with an nominal total output capacity of 526,700 kW; Overload capacity 577,000 kW.
  • Spillway – Constructed 1933-37; 18 gates over a length of 442 m (1,450 ft); maintains the reservoir (upriver) usually 18 m (59 ft) above the river on the downstream side;
  • Second Powerhouse – Constructed 1974-82; Dam 300.5 m (986 ft) long x 77 feet (23 m) high forebay; 8 generators (plus two at fish ladders) with a nominal total generating capacity of 558,200 kW; Overload capacity 612,000 kW.
  • Bonneville Lock – Constructed from 1987 to 1993 at a cost of $341 million; 26 m (85 ft) wide, 206 m (676 ft) long; transit time is approx. 30 minutes. Replaced earlier smaller lock built 1938.
  • Lake Bonneville – 77 km (48 mi) long reservoir on the Columbia River created by Bonneville Dam; part of the Columbia-Snake Inland Waterway.
It was declared a National Historic Landmark in 1987.

The fish hatchery and dam are open year-round from 9:00 am to 5:00 pm. It is best to visit the dam in the months of April through September when the salmon are more abundant.

There are fish viewing windows and visitors' centers on both the Oregon and Washington sides of the dam. Because of security concerns, visitors may be required to show ID, and it is not possible to cross the entire dam. During most of the year, more fish use the Washington shore fish ladders, so fish viewing may be better on the Washington side of the dam.
Bonneville Dam
Locale Columbia River Gorge National Scenic Area, Multnomah County, Oregon / Skamania County, Washington, USA
Construction began 1934 (First Powerhouse)
1974 (Second Powerhouse)
Opening date 1937 (First Powerhouse)
1981 (Second Powerhouse)
Dam and spillways
Type of dam Concrete gravity, run-of-the-river
Impounds Columbia River
Type of spillway Service, gate-controlled
Reservoir
Creates Lake Bonneville
Power station
Type Yes
Turbines 20
Installed capacity 1092.9 MW