Davis Dam impounds the Colorado River and forms Lake Mohave. The dam impounds the Chickamauga Lake and feeds into Nickajack Lake. A dam impounds the river and creates Mackay Reservoir. The dam impounds the Allegheny River near Downtown Pittsburgh. A volcanic dam impounds the lake waters. Another reservoir, Lake Catherine, impounds the Ouachita just below Lake Hamilton. The dam impounds the Helena River. The dam impounds the Nickajack Lake and feeds into Guntersville Lake. The dam impounds the Colorado primarily for hydroelectricity generation. The dam impounds Willow Creek to create Willow Creek Lake. West of Madras, Round Butte Dam impounds the Deschutes River, creating Lake Billy Chinook. The dam impounds the Lake Nottely of . Within the forest is Kinzua Dam, which impounds the Allegheny River to form Allegheny Reservoir. The dam is high and forms Theodore Roosevelt Lake as it impounds the Salt River. The lake is formed by the Santiago Dam, which impounds Santiago Creek.