Flat Rock (Idaho)
Caribou-Targhee National Forest — lakeside, fishing, hiking
Location: ISLAND PARK, ID, ID
Price: From $25 per night
Price range: $25–$62 per night
Rating: 4.4 out of 5 (77 reviews)
Season: May through October
Flat Rock Campground is located 22 miles south of West Yellowstone, Montana and 30 miles north of Ashton, Idaho in beautiful Island Park, Idaho. Highway 20 and the Henry’s Fork of the Snake River at an elevation of 6,400 feet.Island Park is composed of two areas of extinct volcanic activity. The Henry’s Fork Caldera sits inside the larger Island Park Caldera.
Cell coverage (FCC estimate): strong signal. Actual signal may vary in remote areas. Best carrier: T-Mobile. Verizon 4G: 100%. AT&T 4G: 100%. T-Mobile 4G: 100%.
Amenities: Fire Rings, Picnic Tables, Vault Toilets, Drinking Water, Showers, Electric Hookups, Fishing, Boat Launch
Availability alerts: Set a free cancellation alert at camperwatch.org/campground/flat-rock-idaho to be notified when sites open up.
Flat Rock offers excellent fly-fishing on Henry's Fork of the Snake River with access to Big Springs, one of the nation's largest springs just 4.5 miles away. Campers praise the large sites in Loop B, clean facilities, and attentive camp host.
Wildlife alert: Gray Wolf, Shiras Moose, Bald Eagle, and Pronghorn documented in the area within 8km of campground.
Insider tips for Flat Rock (Idaho): Book early — this is a federal campground with high demand. Loop B has larger sites compared to other loops. ATV parking is available at the campground. Rates are $25/night for dry camp and $31/night for electric hookups.
Skip Flat Rock (Idaho) if: You need water or sewer hookups — only electric hookups available on select sites.. You require year-round camping — seasonal operations May through October only.. You have a barking dog — camp host enforces noise policies strictly..
Best time to visit Flat Rock (Idaho): May-October — Official operating season for Flat Rock Campground.. Memorial Day Weekend — Camper reports indicate full capacity but uncrowded conditions during this peak period..
Nearby campgrounds: Upper Coffee Pot (ISLAND PARK, ID), Big Springs Warming Hut (ISLAND PARK, ID), Mccrea Bridge (ISLAND PARK, ID), Big Springs Grp. Area - Island Park (ISLAND PARK, ID).
Cell Phone Coverage at Flat Rock (Idaho)
Cell signal at Flat Rock (Idaho) (ISLAND PARK, ID): strong overall signal based on FCC broadband data. Best carrier: T-Mobile.
- Verizon 4G LTE: 100% coverage · Verizon 5G: 100%
- AT&T 4G LTE: 100% coverage
- T-Mobile 4G LTE: 100% coverage · T-Mobile 5G: 100%
Coverage data source: FCC Broadband Data Collection (BDC). Actual signal may vary due to terrain, tree cover, and distance from towers. Camper reports are more reliable than coverage maps in remote areas.
Flat Rock Campground is located 22 miles south of West Yellowstone, Montana and 30 miles north of Ashton, Idaho in beautiful Island Park, Idaho. Highway 20 and the Henry’s Fork of the Snake River at an elevation of 6,400 feet.Island Park is composed of two areas of extinct volcanic activity. The Henry’s Fork Caldera sits inside the larger Island Park Caldera.
Verified facts
RIDB / Recreation.gov official databaseAmenities
RIDB /facilities /campsites · owner-verifiedStraight talk
CamperWatch intel · curated from camper reportsKnown issues, each with the workaround. Read before you book.
Insider tips & when to go
CamperWatch intel · hand-curated entryBook early
this is a federal campground with high demand.
Loop B has larger sites compared to other loops.
ATV parking is available at the campground.
Rates are $25/night for dry camp and $31/night for electric hookups.
Official operating season for Flat Rock Campground.
Camper reports indicate full capacity but uncrowded conditions during this peak period.
Things to do nearby
RIDB /activities /recareas + intelConditions today
LiveCell signal
FCC BDC · quarterly datasetFCC maps are theoretical — camper reports confirm signal. Best carrier: T-Mobile.
Wildlife nearby
iNaturalist · research-grade · 8 kmLocation
Leaflet · OpenStreetMap tiles
Getting there →
From 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.
Campground entrance
Google Maps APICommunity
#community · posts, photos & Q&A · AI-moderated (Claude Vision)Pro tips
- Book on recreation.gov exactly 6 months ahead at 10am ET — Caribou-Targhee National Forest fills fast in peak season.
- Check current road conditions at Caribou-Targhee National Forest before arrival — seasonal closures common.
- Bear country — store all food in bear boxes or locked vehicle at all times.
Frequently asked questions
RIDB facts + intel · FAQPage schema, speakableHow much does Flat Rock (Idaho) cost per night?+
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Official resources
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