Bad Medicine Lake is a spring-fed lake located in Forest Township in Becker County, Minnesota. It got its name from the fact that early Native Americans in the area thought that a lake with neither inlet nor outlet was a place of bad omen ("bad medicine") and would not hunt or fish near the lake. The lake is approximately five miles long, a half mile wide, and reaches depths of up to 90 feet (27 m). It is known for its clear, cold waters and rainbow trout fishing.