Sanders County is located in Northwestern Montana. It is bordered on the west by Idaho's Panhandle and is Montana's 18th most populous county with approximately 11,000 residents. The county was established in 1905 and named after Wilbur Fisk Sanders, pioneer and U.S. Senator from Montana.
The Clark Fork River, a tributary of the Columbia, runs the length of the valley in Sanders County. The county also encompasses the Cabinet Mountain Wilderness and two National Forests.