Melstone is a rural small town in far eastern Musselshell County, Montana, United States, along U.S. Route 12. The population was 126 at the 2020 census. The town was established in 1908 as a base for operating crews on the Chicago, Milwaukee, St. Paul and Pacific Railroad, then under construction in Montana. Although the railroad was abandoned in 1980, Melstone survives as a community center for farmers and ranchers in the lower Musselshell River valley.