There are at least 6 named lakes and reservoirs in Fallon County, Montana.
- Buffalo Reservoir, 46°15′57″N 104°09′19″W / 46.26583°N 104.15528°W / 46.26583; -104.15528 (Buffalo Reservoir), el. 3,025 feet (922 m)[2]
- Lake Baker, 46°22′06″N 104°16′20″W / 46.36833°N 104.27222°W / 46.36833; -104.27222 (Lake Baker), el. 2,963 feet (903 m)[3]
- Rush Hall Reservoir, 46°35′54″N 104°16′30″W / 46.59833°N 104.27500°W / 46.59833; -104.27500 (Rush Hall Reservoir), el. 3,002 feet (915 m)[4]
- South Sandstone Reservoir, 46°20′20″N 104°28′41″W / 46.33889°N 104.47806°W / 46.33889; -104.47806 (South Sandstone Reservoir), el. 2,861 feet (872 m)[5]
- Sportsman Pond, 46°09′59″N 104°23′34″W / 46.16639°N 104.39278°W / 46.16639; -104.39278 (Sportsman Pond), el. 3,287 feet (1,002 m)[6]