12-mile long reservoir situated among scenic red shale, juniper canyons, and the open prairies of southeastern Montana.
Excellent fishing, wildlife viewing (osprey, blue herons, deer, antelope, bald eagles). Aquatic Invasive Species (AIS) prevention is important.
Montana State Parks camping sits between wild Forest Service sites and private RV parks: clearer rules, maintained facilities, and often water or showers, while still keeping you close to the landscape the park was created to protect.
Nearest town: Decker. Elevation about 3200 feet.
Campground snapshot
- Agency / unit: FWP — State Parks
- Sites: 164
- Type: Tent/RV
- Fee range: $4-$34
- Season: May-Sep
- Reservations: ReserveAmerica or FCFS
- Best for: Tongue River Reservoir
Amenities
fire ring, picnic table, dump station, water faucets, fish cleaning station, vault toilets, boat ramps with docks
How to book
Montana State Parks camping generally books through ReserveAmerica or FCFS. Peak season is typically late May through mid-September. Confirm cabin/yurt options and current fees on the park page. Official listing: fwp.mt.gov/stateparks/tongue-river-reservoir.
Bear country & campcraft
Keep a clean camp even on the plains and eastern reservoirs. Store food and trash securely, and follow any posted food-storage orders.
Campfires belong only in provided metal rings when restrictions allow. Drown, stir, and feel the ashes with the back of your hand before leaving or sleeping. In Stage II restrictions, open fires are banned even in developed sites—use a shut-off stove only.
Follow Leave No Trace: camp on durable surfaces, pack out everything you pack in, and leave the site cleaner than you found it.
Plan the rest of the trip
- Camping reference: reservations, bears, and fire rules
- Open this stop on the Backroads Guided Trails map
- Campgrounds directory
Visitor Access
- Nearest town: Decker
- Focus: State Park
- Coordinates: 45.1331, -106.7633
- Access note: Confirm road conditions, water availability, and fire restrictions before arrival. Mountain weather can drop below freezing even in midsummer.
- Legal reminder: Follow agency food-storage orders, stay within designated sites in developed camps, and respect private land and tribal boundaries.