This is one of the impressive mountain lakes of Oregon, on the east slope of the Cascade Range just southeast of Diamond Peak. It is fed principally by Summit Creek, and its outlet is Crescent Creek, which flows into Little Deschutes River. Its south shore is skirted by the old Oregon Central Military Road, and the Southern Pacific Cascade Line passes a little to the east of the lake. It is named because of its shape. Evelyn Lynes Reeve, a long-time resident of the area, states in An Illustrated History of Early Northern Klamath County, pg. 123, that Native Americans called it Simax Lake. See Simax Bay. The normal elevation is about 4,837 feet, but there is some variation due to water storage. USGS Professional Paper 9 describes this lake in detail. The geography of the lake and its immediate surroundings are shown on the USGS maps of the Crescent Lake, Odell Lake, and Summit Lake quadrangles. Crescent Lake was named in July 1865, by B. J. Pengra and W. H. Odell while making a reconnaissance for the Oregon Central Military Road. Pengra's report, dated November 29, 1865, is in part on file at the Oregon Historical Society.