HD 331 covers the Big Snowy Mountains south of Lewistown—one of central Montana's distinctive island ranges, rising abruptly out of the surrounding prairie like a long limestone whaleback. Elevations climb from about 4,500 feet on the prairie at the base to 8,681 feet at Greathouse Peak, the high point. The range is essentially one long ridge with deep limestone canyons cut into the flanks. The rim country up top is alpine-feeling—wind-scoured grass, scattered limber pine and whitebark, with active glacial-feeling cliffs and the remarkable Ice Caves on the south side that hold ice year-round. The mid-elevation flanks are dense lodgepole and Douglas fir; the lower slopes are open ponderosa parkland and aspen groves on creek drainages. The Big Snowys hold a self-sustaining mountain goat population (transplanted decades back), good elk numbers, mule deer, and one of the most striking trophy-quality bighorn herds in central Montana on adjacent ranges. The compact size means the unit hunts smaller than it looks on a map. Helena-Lewis and Clark NF on the upper range, with private ranch ground (Wilks brothers and several others) ringing the base. Forest roads climb from US-87, MT-200, and county roads—Crystal Lake Road climbs to a popular trailhead and campground on the south side; Half-Moon Road and the Half-Moon Pass area on the east. Lewistown has full services. Roundup is south. Cell service holds in town and dies on the ridge. Mountain goat tags are limited-permit and hard to draw; elk hunts are managed actively and check current regs. The country is steep enough to require real fitness and the limestone makes for sketchy ankle work. Genuinely high-quality island range hunting in a compact footprint.