Custer County, MT is located in south central Montana between Yellowstone National Park and Fort Peck Reservoir on US Highway 212 and HWY 78 junction crossing towards Miles City east side at this location also intersects I94 interstate highway creating direct route towards Minneapolis/St Paul Minnesota if travelers choose that direction for their journey . The county was formed from part of Dawson in 1914; it had an estimated population count 4994 by 2020 estimates where agriculture & ranching remain primary industry jobs supported by cattle grazing upon open range whilst archaeological sites reveal ancient living culture relics scattered about sparsely populated expansive terrain covered mostly by rangeland rolls bounded by geographic mountains rising outwards from this central hub upon big sky landscape neighbored all about 3 sides into adjoining Daniels Rosebud Indian reservation hosted tribes along eastern edge .