The Dalles Dam extends 1 1/2 miles from the Oregon shore to the navigation lock on the Washington shore. Because the boundary between the two states follows the old river channel, The Dalles Dam is almost entirely in the state of Washington.
The dam complex consists of a navigation lock, 1,380-foot-long spillway, 23 gates, powerhouse and fish passage facilities.
Lewis and Clark camped along this stretch of the Columbia some consider The Dalles as the end of The Oregon Trail.

"Plateau families traveled in the spring to harvest salmon. The most famous of these ancient sites was Celilo Falls. The turbulent water there were perfect for generating electricity. Despite passionate resistance by Plateau tribes, Celilo Falls was flooded by the Dalles Dam in 1957 to provide electricity and irrigation water for the Northwest.
Plateau people consider the loss of the Falls, a sacred site, a sorrowful landmark of history."
(quote from the High Desert Museum)