Butt Creek starts on the slopes of Humbolt Peak. The small freestone runs Southeast. The creek flows through pocket water, tail outs and small meadows. Butt Creek was dammed in 1924 to form Butt Valley Reservoir.
Butt Valley Reservoir is an impoundment constructed by the Great Western Power Company in 1924. The reservoir is five miles long and a mile wide. the covers over 1600 surface arces when full. It sits at 4125 feet in elevation.
Butt Valley supports a trophy trout fishery. Angling at the north end of the lake near the Butt Valley Powerhouse is very productive by shore. This small peninsula forms an esturary with Butt Creek enters the lake on one side and on the other side the water from the powerhouse. The powerhouse receives water from Lake Almanor via the Prattville Tunnel. Pond Smelt are transported from Lake Almanor to Butt Valley ending up at the power-house. The smelt are easy prey for hungry trout at Butt Valley.