The Midnite Mine is an inactive former uranium mine in the Selkirk Mountains of the American state of Washington that operated from 1955-1965 and again from 1968-1981. Located within the reservation of the Spokane Tribe of Indians, it is approximately from Wellpinit, Stevens County. The mine was listed as a Superfund site under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) on May 11, 2000. In addition to elevated levels of radioactivity, heavy metals mobilized in acid mine drainage pose a potential threat to human health and the environment.