Cultus Lake is a lake in Deschutes County, Oregon. Formed by a glacier, it is located in the high Cascade Range in the Deschutes National Forest. The name is from the Chinook Jargon, and means variously bad or worthless, or simply "in vain".[1] In the early 1800s, the lakes in this area abounded with beavers. The earliest explorers to this area were primarily on a quest for furs.