Idaho · River fishing

Flat Rock

Flat Rock
May–Sep
best months

Caution at last check

Agency alerts are in effect for this area; weather is good · USFS, OpenWeather · checked 13 h ago

Is Flat Rock open right now?

No closures listed

The Forest Service lists no closures for Caribou-Targhee National Forest.

As of · Source: USFS · Caribou-Targhee National Forest. Agencies don't list every closure — check before you go.

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. Island Park Reservoir and Henry's Lake are nearby, both offer boating, water skiing and excellent fishing opportunities.Facilities The campground contains single and double campsites, some of which have 50-amp electric hookups. Sites are equipped with picnic and utility tables, a campfire ring and tent pad. Vault toilets, drinking water and trash collection are provided. All interior roads and parking spurs are gravel. Macks Inn is just across the highway from the campground and offers amenities such as boat rentals, shuttle service, showers, laundry facilities, gas and groceries. Natural Features Island Park is composed of two areas of extinct volcanic activity. The Henry's Fork Caldera sits inside the larger Island Park Caldera. The area is known for its dense forests of lodgepole pine, broad grassy meadows bursting with summer wildflowers and a wide variety of wildlife, including black and grizzly bears, moose, elk, deer, bald eagles, Sandhill cranes and much, much more. A mixed growth of lodgepole pine forest provides partial shade. A portion of one loop is fairly close to the river and some sites have river views. Nearby Attractions Mesa Falls Scenic Byway is 11 miles south of the campground. This 28-mile road leads to scenic overlooks and trails at 110 foot Upper Mesa Falls and 85 foot Lower Mesa Falls. Harriman State Park is 13 miles south. The Henry's Fork meanders through the Harriman, offering excellent fishing. Over 20 miles of trails are available, and wildlife is abundant in this scenic park. Henry's Lake State Park is 10 miles north, offering fishing, a fish cleaning station and boat ramp. Yellowstone National Park's west entrance is just 22 miles north in the town of West Yellowstone, Montana. Visitors enjoy day-tripping to the park for unparalleled wildlife viewing and the beautiful and unique scenery.

Local outfitters

Not on Roamze yet. Their page has how to reach them.

  • Best time to go · May–Sep

    Best time to visit Flat Rock

    Best months: May–September. Best months have typical highs of 55–85 °F, lows of 30 °F or warmer (32 °F where the station doesn't record snow), at most one snowy day and no more than 12 wet days.

    1. Jan

      27° / 6°

    2. Feb

      30° / 7°

    3. Mar

      39° / 14°

    4. Apr

      47° / 23°

    5. May

      59° / 32°

    6. Jun

      67° / 38°

    7. Jul

      77° / 43°

    8. Aug

      77° / 40°

    9. Sep

      68° / 32°

    10. Oct

      51° / 24°

    11. Nov

      36° / 14°

    12. Dec

      25° / 6°

    Typical high / low (°F) and days with rain or snow, 1991–2020. Measured at Island Park, ID, 5.6 mi away at 6,290 ft. This station doesn't record snowfall. Source: NOAA NCEI U.S. Climate Normals 1991–2020.