Big Horn County is situated in southeast part of Montana near Billings. It covers 8290sq mi across which resides 10702 people ( 2020 ) making among least densely populated regions within state boundaries . Hardin serves as its county seat while other townships include Busby , Crow Agency & Garryowen along with several unincorporated places inhabited by native peoples . Agriculture provides most economic returns as majority land here used for livestock farming or cultivation while industries also contributes significantly to local economy through coal mining operations apart from few small businesses offering products related to tourism industry like fishing gear or camping equipment etc.