🌤 Weather at Marias River State Park by season
| Spring | Summer | Fall | Winter |
|---|---|---|---|
| 20–66 °F | 46–82 °F | 20–71 °F | 11–37 °F |
Each range runs from the coldest monthly average low to the warmest monthly average high in that season (1991-2020 climate normals), measured at Conrad, 10 mi away, elevation 3,550 ft. Conditions at the park can differ from the station, especially where elevation differs — check a forecast before you go.
🦌 Undeveloped River Park — An undeveloped Montana state park managed together with FWP’s 8,865-acre Marias River Wildlife Management Area southwest of Shelby
Marias River State Park is an undeveloped Montana state park on the Marias River southwest of Shelby. It has no visitor facilities of any kind. Montana Fish, Wildlife & Parks (FWP) manages it together with the Marias River Wildlife Management Area (WMA), which FWP bought in 2009. The WMA covers 8,865 acres in Toole and Pondera counties and an undeveloped 14-mile stretch of the river, with sagebrush grassland and short-grass prairie. FWP does not publish a separate acreage for the state park itself, so you will see different figures elsewhere.
Because there is no park infrastructure, the WMA rules are the ones that matter on the ground. They are seasonal, they limit vehicles to a few roads, and deer hunting runs on a permit drawing.
Access and Rules
- Season: The WMA is open from noon on April 1 to 11:59 PM on January 1 (FWP brochure, revised June 2025).
- Roads: From Hjartarson Road, the McCormick Access Road leads to the northwest corner of the WMA and the Clark Access Road to its north-central part. Motor vehicles, including e-bikes and off-highway vehicles, are allowed only on designated open roads. The Lincoln Access Road is open only to holders of a WMA deer hunting access permit during their season.
- Camping: Motorized camping is limited to the designated parking areas off the McCormick and Clark access roads. Non-motorized camping is allowed more than a quarter mile (440 yards) from those parking areas. There are no campgrounds and no reservations.
- Floating: FWP rates the Marias a Class I river, suitable for beginners at normal flows. FWP names Sullivan Bridge, about 13 miles north of Valier, as a put-in and Williamson Park, 1.2 miles below the I-15 bridge, as a take-out.
Hunting
Deer hunting access on the WMA is assigned by a random drawing in Hunting District 406; for 2026, applications closed on June 30. Hunting for all other species is open without a drawing under Montana’s regular seasons and licenses.
Park Information
| Feature | Details |
|---|---|
| Type | Undeveloped state park, managed with the Marias River WMA |
| WMA size | 8,865 acres, Toole and Pondera counties |
| Facilities | None |
| Season | April 1 (noon) to January 1 |
| Contact | FWP Region 4, Great Falls: (406) 454-5840, Mon–Fri 8 AM–5 PM |
Frequently Asked Questions
Can you drive to Marias River State Park?
Partly. You can drive Hjartarson Road and the designated McCormick and Clark access roads to their parking areas, but not beyond them. The interior and the river are reached on foot, on horseback or by floating. Check the current WMA map from FWP Region 4 at (406) 454-5840 before you go.
Keep exploring: The closest neighbors are First Peoples Buffalo Jump State Park (elsewhere in the state) and Giant Springs State Park (elsewhere in the state).
Sources: Montana FWP, Marias River WMA brochure (revised June 23, 2025) and WMA access page; FWP/MEPA draft environmental assessment (2011). As of October 2026.
🐾 Dogs & Pets at Marias River State Park
- Pets allowed? statewide rule
- Pets are allowed at most Montana state parks but must be leashed and not left unattended.
- Leash rule statewide rule
- Leash no longer than 8 feet required, unless otherwise posted.
- Beaches & swim areas statewide rule
- Pets are prohibited from swimming beaches and posted restricted areas.
- Statewide exceptions statewide rule
- Pets prohibited at Frenchtown Pond and Wild Horse Island; kennel service offered during Lewis and Clark Caverns tours; Spring Meadow Lake no pets April 16 - October 14; Lake Elmo has a fenced dog park.
Are dogs allowed at Marias River State Park?
Pets are allowed at most Montana state parks but must be leashed and not left unattended. Individual parks can post stricter rules — check signage on arrival.
Rules verified July 2026 via fwp.mt.gov. More: Montana state parks guide · Dog rules in all 50 states compared
Park Map
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