The United States Congress designated the Medicine Lake Wilderness (map
) in 1976 and it now has a total of 11,366 acres
All of this wilderness is located in Montana
and is managed by the Fish and Wildlife Service.
Medicine Lake Wilderness lies within the glacial drift prairie of northeastern Montana. The gentle rolling hills and numerous shallow wetland depressions were created by repeated advances and retreats of glaciers. More than 12,000 years ago, a one to three mile-wide valley bordered by pre- and postglacial terraces was formed by a glacial front along the ancient route of the Missouri River. Sitting at about 2,000 feet in elevation, Medicine Lake is a large, shallow lake which filled this ancient valley. The Medicine Lake Wilderness includes the main water body of the lake, the islands within the lake, and a portion of land southeast of the lake. Receiving 12.83 inches of precipitation, annually in the Wilderness, average temperatures range from 55 to 84 degrees F in July, but can rise above 100 degrees in the summer. Summer nights almost invariably are cool and pleasant. In January, average temperatures range from -2 to 23 degrees.
The Medicine Lake Wilderness conserves diverse wetlands and grasslands to provide breeding grounds for migratory birds and other wildlife. Over 126 species of birds are documented to breed in the area, including an abundance of waterfowl, grassland birds and colonial nesting birds. The most common grasses are needle and thread grass, blue grama, western wheatgrass, prairie junegrass, and prairie sandreed. Four state-listed noxious weeds are found on the Wilderness: leafy spurge, Canada thistle, spotted knapweed, and dalmation toadflax. These noxious weeds are being intensively managed.