Cougar Dam, Embankment dam in Lane County, Oregon.

Cougar Dam is a 519-foot (158 m) rockfill embankment dam on the South Fork McKenzie River, about 42 miles east of Eugene, Oregon. Its gated concrete spillway and powerhouse with two turbines totaling 25 megawatts impound Cougar Reservoir, which has a storage capacity of 219,000 acre-feet. The dam is approximately 1,500 feet long and includes a diversion tunnel closed with a concrete plug.

Cougar Dam was completed in 1963 at a cost of $54.2 million, and its two turbines were finished in 1964. It operates with Blue River Dam for flood control and has prevented an estimated $452 million in flood damages. In 2005, a temperature control facility was added, and a fish collection and sorting facility was completed in 2010.

The reservoir and river below the dam are used for fishing and boating, and the surrounding Willamette National Forest land offers trails. The name comes from Cougar Reservoir, which the dam impounds on the South Fork McKenzie River. The U.S. Army Corps of Engineers runs a fish collection and sorting facility below the dam, where adult salmon and bull trout are loaded onto trucks and released into habitats above the reservoir.

The reservoir level varies widely for flood control, so boat ramps and shoreline access can change; check conditions before launching. The fish collection facility below the dam is not open to visitors. The 302-foot wet well and adjustable gates are visible from the dam crest.

The facility uses special turbine outlets to draw water from different layers of the reservoir to help manage downstream water temperature. This approach provides better conditions for fish migrating downstream.