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Tongue River Reservoir State Park

Enjoy this 12-mile long reservoir situated among scenic red shale, juniper canyons, and the open prairies of southeastern Montana. The park is loved by Montana and Wyoming anglers, campers, and boaters. It provides excellent fishing as numerous "state record" fish have been pulled from its waters.

About the Park

Among the rolling, prairie hills of Southeastern Montana, Tongue River Reservoir State Park is a rare and loved place where many come to enjoy water-based activities at their best. This lake is a great place for creating memories.

Fishing, boating, swimming, and camping are the prime activities here, and the reservoir boasts excellent crappie, walleye, bass and northern pike fishing. Fly fishermen can test their skill on the river below the dam. Wildlife viewing is also plentiful, with osprey, blue herons, deer, antelope as well as a few bald eagles being regular summer sights.

The park offers 81 reservable camping sites with electric hookups, with 27 of those being double occupancy campsites (two electric hook-ups), as well as over 69 non-reservable, non-electric camping sites. Most sites have a fire ring and a picnic table. A dump station and water faucets are available during peak season, as weather permits. The park also has a fish cleaning station and over 20 vault toilets throughout the campgrounds. There are 2 boat ramps with docks for launching boats, one at Campers Point by the marina and one at Pee Wee North.

Reservations for camping are available peak season which is defined as the third Friday of May until and the third Sunday of September. Reservations can be made 3 months in advance. During off season, all sites are "first come, first serve" or "walk-in."

Day use areas include sheltered picnic tables at Campers Point and Sand Point. Sand Point has a small, but popular “beach area” for swimming and picnicking.

A marina store at Campers Point offers firewood, ice, fishing and boating supplies, boat rentals, boat and RV storage, bait, groceries, snacks, drinks, gasoline, souvenirs, fishing and hunting licenses and non-resident park passes.

In the winter, Tongue River Reservoir is a popular ice fishing location. Eleven campsites on Campers Point have electricity year-round. During the off season, all sites are first come, first serve. 

The park is 642 acres in size at an elevation of 3,468 feet.

Hiking and historical opportunities are available nearby at Rosebud Battlefield State Park, Little Big Horn Battlefield National Monument and in Sheridan, Wyoming.

Please contact the park regarding any hunting regulations.

Park office hours during peak season are 8am to 4pm daily.


  • Bird Watching
  • Camping
  • Canoeing
  • Fishing
  • Ice Fishing
  • Ice Skating
  • Kayaking
  • Lake Fishing
  • Motor Boating
  • Paddle Boarding
  • Photography
  • Picnicking
  • RV Camping
  • Swimming
  • Tent Camping
  • Tubing
  • Water Skiing
  • Wildlife Viewing
  • Wind Surfing


Some amenities are seasonal. Check with the park for availability.

  • ADA Accessible
  • Boat Launch
  • Boat Rental
  • Electricity
  • Established Fire Pits
  • Firewood for Sale
  • Fishing Bait
  • Grills/Fire Rings
  • Licenses Available for Purchase
  • Maps
  • Parking
  • Pets Allowed
  • Picnic Shelter
  • Playground
  • RV Dump Station
  • RV Hookups
  • Store
  • Toilets (Vault)
  • Trash Removal
  • Water (Potable)

Seasons & Hours

Hours listed below are normal operating hours and may not apply when there is a special restriction or closure. Check Alerts and Closures in the tab below.

Open daily all year


  • Open year round
  • Electricity available at Camper's Point and Pee Wee South Campgrounds - availability reduced during off season. Only 11 sites have electricity from approximately October 1st to May 1st depending on weather.
  • Group areas & playground are open

Water & Fish Cleaning Stations
Available approximately early-May through Sept. 30th depending on weather

Alerts & Closures

Restrictions and Closures

See a current list of Restrictions and Closures on State Parks and other FWP lands that may be affected by floods, fire, drought or major maintenance activities.

Park Rules


Contact the park manager for open volunteer positions at Tongue River Reservoir State Park.

For complete position descriptions, application forms, and details about Montana State Parks volunteer programs, visit the Volunteers page.


Montana Residents

  • Montana residents who pay the $9 state parks fee with their annual vehicle registration have no daily entrance fees to state parks. For residents who don't include this in their vehicle registration, non-resident day use fees apply.



  • Day use entrance fee with a vehicle: $8
  • Day use entrance fee as a walk-in, bicycle or bus passenger: $4
  • With a Nonresident Entrance Pass: Free



  • Campsite fees range from $4-$34 per night, depending on season and available amenities.

Montana State Parks offers hike/bike, rustic, tent, rv, and boatslip campsites. 

Visit Reserve America to check fees and reserve a campsite for Tounge River Reservoir State Park.

Contact Information

Mailing Address:
Tongue River Reservoir State Park
PO Box 8
Decker, MT 59025

Phone: 406-757-2298


Reservation Phone Number:


Aquatic Invasive Species

Help protect Montana's waters

AIS can be easily spread from one waterbody to the other. Anglers, boaters, construction workers, pond owners, gardeners, seaplane pilots, field workers - virtually anyone who works or plays in or around water can unknowingly transport these pests on their boats and equipment. It takes only one mistake to potentially infest a new water body.

Prevent the spread of AIS 

Tongue River Reservoir State Park


292 Campers Point
Decker, MT 59025
(45.09975 / -106.79453)

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Park map

View the park map to learn more about amenities, parking and camping details

View Park Map 
Park fees

Learn about fees and regulations for all Montana State Parks

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Meet The Park Manager

Raymond Schell

Raymond Schell, Park Manager at Tongue River and Rosebud Battlefield state parks, had over 20 years’ experience working in parks in Arizona and Alaska before joining the Montana State Parks system in 2017. Prior to moving to Tongue River, Raymond managed White Tank Mountain Regional Park, a popular 30,000 acre recreation area west of Phoenix, AZ. Before that, he worked for 8 years at Denali National Park, AK.

Mailing Address:
Tongue River Reservoir
PO Box 8
Decker, MT 59025

Phone: 406-757-2298

Photo of Park Ranger Raymond Schell