[6] The dam is located 40 miles (64 km) east of Portland, Oregon, in the Columbia River Gorge.

At the time of its construction in the 1930s it was the largest water impoundment project of its type in the nation, able to withstand flooding on an unprecedented scale.

Prior to the New Deal, development of the Columbia River to provide flood control, hydroelectricity, navigation, and irrigation was deemed to be important.

During this period, America was in the Great Depression, and the dam's construction provided jobs and other economic benefits to the Pacific Northwest.

Eventually a new lock was needed at Bonneville; this new structure was built on the Oregon shore, opening to ship and barge traffic in 1993.

California sea lions are also attracted to the large number of fish, and are often seen around the base of the dam during the spawning season.

[14] By 2006, the growing number of sea lions and their impact on the salmon population had become worrisome to the Army Corps of Engineers and environmentalists.

[15][16] Historically, pinnipeds such as sea lions and seals have hunted salmon in the Columbia River as far as The Dalles and Celilo Falls, 60 miles (97 km) farther upstream from Bonneville, as remarked upon by people such as George Simpson in 1841.

[17] Creating electricity was a sensitive issue at the time of the Bonneville Dam's construction, which was funded with federal dollars.

The Franklin D. Roosevelt administration wanted the electricity produced to be a public source of power and prevent energy monopolies.