Mountain Home is the largest city and the county seat of Elmore County, Idaho, USA. The population was 14,206 at the 2010 census. Mountain Home is the principal city of the Mountain Home, Idaho Micropolitan Statistical Area, which includes Elmore County.Mountain Home was originally a post office at Rattlesnake Station, a stagecoach stop on the Overland Stage Line, about seven miles (11 km) east of the city, on present-day US-20 towards Fairfield.