The Dalles Lock and Dam

The Dalles Lock and Dam was one of the largest, most complete, and complex multipurpose projects of its kind in the United States at the time of its construction. It provided an example for future projects benefitting navigation, recreation, water for irrigation and hydropower, fish migration, and flood mitigation. The unusual "L" configuration of the project enabled reduced construction dewatering and created a permanent shallow stilling basin that aids fish passage.