Dworshak Dam

Dworshak Dam is a concrete gravity dam in the western United States, on the North Fork of the Clearwater River in north centralIdaho. In Clearwater County, the dam is located approximately four miles (6 km) northwest of Orofino and impounds the Dworshak Reservoir for flood control and hydroelectricity generation. By capacity, the reservoir is the largest in Idaho and fourth-largest in the Pacific Northwest.

With a height of 717 feet (219 m), Dworshak is the third tallest dam in the U.S. and the tallest straight-axis concrete dam in the Western Hemisphere. Construction of the dam by the U.S. ArmyCorps of Engineers (USACE) began in 1966 and was completed in 1973.

Lacking fish ladders, the dam blocks fish passage and completely extirpated anadromous fish migration into the upper reaches of the North Fork and its tributaries in Idaho.