The CM Ranch and Simpson Lake Cabins are separate components of a single historic district associated with Charles Cornell Moore, a Fremont County, Wyoming dude ranch operator. The CM ranch, named after Moore, operated as a dude ranch from 1920 to 1942 and resumed operating in 1945. The Simpson Lake Cabins were purchased by Moore in 1931 and were operated as a hunting camp, continuing until 1997 when the CM ranch was sold to new owners and the Simpson Lake property was taken over by the U.S. Forest Service.. The sites are separated by 13 miles (21 km).