Overview Flat Rock Campground is located 22 miles south of West Yellowstone, Montana and 30 miles north of Ashton, Idaho in beautiful Island Park, Idaho. Flat Rock is adjacent to U.S. Highway 20 and the Henry's Fork of the Snake River at an elevation of 6,400 feet. Recreation Henry's Fork has great fly-fishing for rainbow and brook trout. The river's headwaters are at Big Springs, one of the nation's largest springs, just 4.5 miles from the campground. Tubing, canoeing, kayaking and rafting are also popular on the river. The Big Springs National Recreation Water Trail begins at Big Springs and ends just northeast of the campground at Macks Inn. It offers a lazy three-hour float or canoe trip through beautiful scenery. Wildlife, including moose, bald eagles and Sandhill cranes, is often seen along the trail. Hiking, biking, horseback riding and ATVing are popular activities. Many miles of trails crisscross Island Park, including the 2.5-mile Coffee Pot Rapids Trail, which begins at nearby Upper Coffee Pot Campground and meanders along the riverbank. The Continental Divide National Scenic Trail and the Nez Perce Trail are in the area.
Source: rec_gov · last verified 2026-05-14