Geyser is in northwestern Judith Basin County in a broad valley between the
Highwood Mountains to the north and the
Little Belt Mountains to the south. U.S. Route 87 runs along the south edge of the community, leading northwest to Great Falls and southeast to
Stanford, the Judith Basin
county seat. According to the
U.S. Census Bureau, the Geyser CDP has an area of , all of it recorded as land. The community sits on a low bench between McCarthy Creek to the east and Crow Coulee to the west. The two creeks flow north to Hay Creek, a tributary of Arrow Creek, which flows northeast to the
Missouri River. ==Demographics==