The Charles M. Russell National Wildlife Refuge (abbreviated as the CMR NWR) is a National Wildlife Refuge in the U.S. state of Montana on the Missouri River. The refuge surrounds Fort Peck Reservoir and is 915,814 acres (3,706.17 km2) in size. It is the second-largest National Wildlife Refuge in the lower 48 states of the United States, and the largest in Montana. Created in 1936, it was originally called the Fort Peck Game Range. It was renamed in 1963 after Montana artist Charles M. Russell, a famous painter of the American West. In 1976, the "range" was made a "refuge" (which legally changed the way the area was managed).