Flat Rock (Idaho)
HIGHWAY 20, ISLAND PARK, ID 83429, USA
Flat Rock (Idaho)
$25.00 - $62.00 / night
Campsite Fees
The campground charges $31-$62 per night for electric hookup sites and $25 per night for non-electric sites during the peak season (May 23 -...
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Standard Site Fee$25.00
Hookup Site Fee$62.00
Premium Site Fee$0.00
Hike and Bike Site Fee$0.00
Group Site Fee$0.00
Food Storage Locker Fee$0.00
Total Campsite Fees$87.00
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Recreation.gov
Provider208-558-7658 OR 208-270-0094
About this campground
Nestled in the heart of Island Park, Idaho, Flat Rock Campground offers an authentic wilderness escape just 22 miles south of the famed West Yellowstone gateway. This scenic retreat along the Henry's Fork of the Snake River provides the perfect basecamp for exploring the Greater Yellowstone ecosystem. Well-appointed with essential amenities including vault toilets, fresh drinking water, and regular trash collection, the campground features sturdy gravel roads and spacious parking spurs that welcome everything from compact cars to full-size RVs. Its convenient location along U.S. Highway 20 makes it easily accessible while still maintaining that coveted off-the-beaten-path feel.
Flat Rock Campground accommodates a range of camping setups with options for tent camping, RVs, and electric sites. No options for primitive or luxury camping are specified.
Historical SignificanceIsland Park tells a dramatic geological story written in volcanic stone and ancient lava flows. The campground sits within a remarkable double caldera system—the Henry's Fork Caldera nested inside the massive Island Park Caldera—remnants of explosive volcanic eruptions that shaped this landscape millions of years ago. These ancient geological forces created the unique ecosystem visitors experience today, from the fertile meadows that bloom with summer wildflowers to the thermal features that hint at the earth's restless energy still simmering below.
Weather and SeasonsPerched at 6,400 feet in the Rocky Mountains, Flat Rock Campground enjoys delightfully cool summers that offer a refreshing escape from valley heat. Daytime temperatures typically hover in the comfortable 70s, while evenings invite cozy campfires as temperatures dip into the crisp 40s and 50s. Winter transforms this landscape into a snow-laden wonderland, though the campground becomes inaccessible as heavy snowfall and sub-zero temperatures dominate from November through April. The shoulder seasons bring their own magic, with wildflower blooms in late spring and golden aspen displays in early fall.
ElevationAt 6,400 feet above sea level, Flat Rock Campground occupies that sweet spot of mountain elevation where the air is refreshingly thin and crystal clear. This altitude blessing means gloriously cool summer nights perfect for sleeping under the stars, though visitors should pack layers as temperatures can swing dramatically between sunny afternoons and starlit evenings. The elevation also treats campers to spectacular night skies, where the Milky Way stretches across the heavens with breathtaking clarity far from city lights.
Natural Features and SceneryImmerse yourself in Island Park's enchanting tapestry of towering lodgepole pines that stretch skyward like nature's cathedral, their evergreen canopy providing dappled shade throughout the campground. Beyond the forest, expansive meadows burst with seasonal wildflowers—purple lupine, golden balsamroot, and delicate paintbrush creating a photographer's paradise. This pristine habitat supports an impressive cast of wildlife characters: majestic moose browsing in marshy areas, bugling elk during autumn rut, both black and grizzly bears foraging for huckleberries, soaring bald eagles fishing the river, and elegant Sandhill cranes performing their ancient dances in nearby wetlands.
Geological RegionFlat Rock Campground rests within one of North America's most fascinating geological wonders—the overlapping calderas of Island Park. This double caldera system, formed by cataclysmic volcanic eruptions, created a unique high-altitude basin that supports an extraordinary diversity of life. The volcanic legacy enriches the soil, nourishing vast lodgepole pine forests that provide shelter for the region's abundant wildlife. Broad meadows carved by ancient lava flows now bloom with wildflowers and serve as grazing grounds for elk and moose. From grizzly bears emerging from hibernation to bald eagles nesting along the river corridors, the geological foundations of Island Park have created one of the Lower 48's last intact ecosystems.
Campsite details
AccessibilityNo specific accessibility features were mentioned in the source materials.
Sites SizeThe sites are described as spacious, with large tent pads and ample room for trailers or RVs.
Sites PrivacyPrivacy levels are high, with sites being 'far apart' and 'well-spaced.'
Total Campsites74 campsites
Recommended CampsitesChoose sites further from the highway to minimize road noise. Electric hookup sites are well-regarded.
Best CampsitesCampers appreciated sites such as B006, B008, B010, B011, B013, and B017 for their cleanliness, spaciousness, and proximity to amenities.
Reserving a campsite
Check-in
Check-in is allowed from 11:00 AM.
Check-out
Check-out is by 12:00 PM.
Stay Limit
You may stay up to 14 nights during a visit at this campground.
Guests Allowed Per Site
Maximum guests per site not explicitly stated.
Groups
No group sites are explicitly mentioned.
Tents
Tents are allowed
RV vehicles
RV vehicles are allowed
Primitive
Primitive are not allowed
Reservable
Reservations are allowed
Site layoutThe campground contains single and double campsites with electric and non-electric options. Interior roads and parking spurs are gravel.
Open and Closed SeasonOpen from May 23 through September 14 (reservable season) annually.
Reservation PlatformsReservations can be made through Recreation.gov, accessible online, via app, or contact center.
Walk-in AvailabilityThis campground has first-come, first-served sites as noted under 'Need to Know' guidelines.
Cancellation PolicyReservations can be canceled any time before the scheduled arrival date for a refund minus a $10 cancellation fee. Late cancellations will also forfeit the first night's fees. No-shows incur a $20 fee and forfeit the first night's fees.
Amenities available
Showers
Potable water
Fire rings
Picnic tables
Vault toilets
Electricity hookups
Laundry Facilities
Activities you can enjoy
Flat Rock Campground offers a variety of recreational activities for outdoor enthusiasts. 'Henry's Fork has great fly-fishing for rainbow and brook trout.' The Big Springs National Recreation Water Trail allows for a scenic three-hour float. Activities like tubing, canoeing, kayaking, and rafting are popular on the river. Hiking, biking, horseback riding, and ATVing are also available, with many trails crisscrossing the Island Park area. Nearby reservoirs and lakes enhance the experience with boating, water skiing, and fishing.
Hiking
The campground is located near the 2.5-mile Coffee Pot Rapids Trail and other major trails such as the Continental Divide National Scenic Trail and the Nez Perce Trail.Fishing
Fishing is a major draw with opportunities to catch rainbow and brook trout at Henry's Fork. Additional nearby fishing spots include the Island Park Reservoir and Henry's Lake.Biking
Biking is a popular activity, with trails in the surrounding Island Park area.Boating
Boating opportunities are available at nearby Island Park Reservoir and Henry's Lake, which offer water skiing and excellent fishing. Canoeing and kayaking are popular on Henry's Fork.Wildlife viewing
Wildlife such as moose, bald eagles, and Sandhill cranes can often be seen along the Big Springs National Recreation Water Trail.Winter Activities
Winter activities are not detailed in the provided information.Water Sports
Tubing, rafting, and kayaking on Henry's Fork are popular water sports available to campers.Campground rules
- Pets are not allowed
- Campfires are allowed within designated rings. Fire restrictions may apply seasonally.
- Quiet hours are Not explicitly stated.
Hazards
General hazardsCommon hazards include road noise from U.S. Highway 20, potential encounters with wildlife such as bears, and seasonal fire restrictions.
Active alertsNo current alerts explicitly mentioned.
Weather forecast
64
°F
Oct 10
Friday
Mainly clear
Precipitation: 0%
Strong wind, exercise caution
Humidity: 48%
Comfortable humidity levels
Wind: 10.8 mph
Strong wind, exercise caution
Mainly clear
7-Day Forecast
Access to 7-day forecasts tailored to each campground—covering temperature, precipitation, wind, and sky conditions.
Daily & Hourly Insights
View hourly forecasts with expected weather patterns throughout the day.
Temperature Trends
Visualize how temperatures shift over the month to help pick the most comfortable days for your trip.
Precipitation Trends
Plan around rain or snow with monthly visualizations of expected precipitation patterns.
Weather Summaries
Assess conditions with visuals for easier decision-making on when and where to camp.
Weather data powered by Open-Meteo
Emergency Services
Closest emergency services are across the highway at Macks Inn, which offers amenities such as gas, groceries, showers, and laundry facilities. Full emergency services would likely be located in nearby towns such as Island Park or Ashton.
Good to know
Peak season datesMay 23 - September 14.
Trash and recyclingTrash collection is provided within the campground. Some reviews mention trash bins becoming full during peak times.
Proximity to water featuresThe campground is adjacent to Henry's Fork, offering fly-fishing, canoeing, kayaking, and rafting. Island Park Reservoir and Henry's Lake are nearby.
Common complaintsMany user reviews highlight the significant road noise due to the campground's proximity to U.S. Highway 20. Complaints also mention inconsistent performance by campground hosts.
HostCampground hosts received mixed reviews, ranging from 'super welcoming and helpful' to 'grumpy and unhelpful.'
Campground Map
HIGHWAY 20, ISLAND PARK, ID 83429, USA
Driving directionsFrom West Yellowstone, Montana, take U.S. Highway 20 south for 22 miles, or from Ashton, Idaho, take U.S. Highway 20 north for 30 miles. The campground entrance is 1/4 mile south of Macks Inn on the west side of the highway.
Flat Rock Campground is adjacent to U.S. Highway 20, making it easily accessible. However, reviews consistently note the proximity to the highway as a source of significant road noise. All interior roads and parking spurs are gravel.Nearby places
West Yellowstone, MT (22 miles, approximately 20-minute drive)
Ashton, ID (30 miles, approximately 30-minute drive)
Island Park Reservoir and Henry's Lake are nearby.
Nearby supplies
Supplies can be obtained at Macks Inn, located directly across the highway, offering boat rentals, shuttle services, showers, laundry facilities, gas, and groceries.
Camper Reviews
4.4
51 reviews

Flat Rock (Idaho) is recommended, placing it in the top 40% of campgrounds based on reviews
Flat Rock Campground has a mixed reception, with many campers praising its cleanliness, spacious sites, and friendly hosts, while others note issues with noise from the nearby highway and inconsistent host behavior.
Review Summaries
Based on 51 reviews
What Campers Love
Cleanliness of campsites and vault toilets, spacious and level sites, friendly and helpful hosts, close proximity to recreational activities, and excellent fishing opportunities. Many reviews commend...
Based on 51 reviewsShow more
Common Concerns
Complaints include road noise from the adjacent U.S. Highway 20, negative experiences with specific hosts, and occasional trash management issues. Some users also found the campground difficult to...
Based on 51 reviewsShow more
Pro Tips & Recommendations
Bring earplugs for highway noise. Book early, as reservations fill up quickly. Use Macks Inn for additional amenities like showers and laundry. Consider nearby Upper Coffee Pot Campground for a...
Based on 51 reviewsShow more
Seasonal Insights
Summer reviews highlight the campground's proximity to Yellowstone National Park and the pleasant outdoor activities available. However, road noise and the campground's popularity during peak seasons...
Based on 51 reviewsShow more
Camper Quotes
1. 'The campground was great, just all the rain and weather made it good.' - LEON B.
2. 'Nice wide level campsite. Access road is dirt, so some dust.' - BRYAN P.
3. 'The camp host Dan and Annie...
Based on 51 reviewsShow more
Site-Specific Reviews
Site B006 received both positive ('very clean and quiet') and negative ('trash in the pit, campfire smoldering') feedback. Site B008 was frequently mentioned as spacious and clean. Road noise was...
Based on 51 reviewsShow more
Accessibility Features
No specific user reviews addressing accessibility features were available.
Based on 51 reviewsPet-Friendly Features
Reviews generally do not mention pet-specific policies, but one user appreciated the campground's dog-friendly atmosphere and walkable distance to Mack's Inn.
Based on 51 reviewsLast updated August 10, 2025