Crater Ice Cave / Big Pryor Mountain Trail

This is a short and steep trail from Tie Flat (near the north end of Crooked Creek Road) to Crater Ice Cave and the top of Big Pryor Mountain. In a distance of 1.7 miles (one way) it climbs 1,600 feet up the northeast corner of Big Pryor Mountain. Much of the climb is through a cool, quiet and secluded Douglas fir forest.

Look for abundant squirrels and occasional dusky grouse. Striped Coralroot, an orchid, may be seen blooming near the trail – perhaps in June. Black bear have also been seen on this trail. Viewpoints are scarce on the lower trail, but peeks through the trees are increasingly frequent on the higher switchbacks. The expansive view from the highest point in the Pryors (8,786 feet elevation) includes East Pryor Mountain, the Bighorn Mountains, the Beartooths, the plains of Montana to the north, and much of Wyoming including the Wind River Mountains to the south. The top of Big Pryor Mountain provides one of the ten biggest views in all of Montana.

Wildflowers can be profuse on the subalpine Big Pryor Plateau in late June or early July. For information about the special subalpine meadow cushion plant community see the Botanical Guide to this area.

This is the only trail in the Pryors designated for motor-free hiking by Custer Gallatin National Forest (CGNF). CGNF should improve the trail signing, and provide public information on this, and other, motor-free routes in the Pryors.

Download a printable Crater Ice Cave / Big Pryor Mountain Hiking Guide

Getting to the Trailhead

Detailed Maps and Driving Directions to Pryor Mountain hiking trailheads are available on the Hiking Overview page.

2.5 miles south of Bridger MT on Highway 310, take Pryor Mountain Road east. About 30 miles from Highway 310, and 0.6 miles before the Crooked Creek Rd junction, turn right (south) on the two track Tie Flat Rd. #2104.

Follow #2104 for 0.1 mile to a junction with a two track trail to the right (southwest). This junction is the trailhead. Route #2104 continues straight ahead with no obvious trail sign. There is a “Crater Ice Cave Trail No. 31” sign, but unfortunately it is poorly placed 100 yards from Tie Flat Rd. where it is hard to see. It is too small to read until you walk much closer. Look for it on the right (southwest). There is a “No Motor Vehicles” sign beside the trail sign.

Please park beside Tie Flat Rd (#2104). Do not drive the 100 yards to the sign. That violates Forest Service regulations - and damages the landscape.

The Trail

Walk southwest up the two-track trail for 0.4 miles. At first it is in open grassland and sagebrush, but soon enters the trees. After 0.4 miles, and 300 ft elevation gain, the track arrives at a flat opening in the trees. The two old logging tracks to the right (north), signed #2002A and #2002A1, are motor-legal, but little used.

A “Crater Ice Cave Trail” sign is visible about 100 feet south (left) on the old road. (The two-track is not motor-legal in that direction.) The trail, a narrow footpath, leaves the old road and enters the gulley to the west (right) just before the sign. See photo.

At first the trail is fairly primitive, formed only by the impact of previous hikers – like a game trail. The trail goes about 40 or 50 feet up the bottom of the gulley, then climbs out the right (north) side. It then continues west paralleling the gulley on its north side for a couple hundred feet through open grass and low brush (snowberry and Oregon grape) before entering thick timber.

As you enter the timber you will see several saw cut logs beside the trail. The trail then makes a right angle turn to the right (north).

From this right turn on the trail follows a quite obvious, old, constructed trail bed about 1 ¼ mile, 1,200 ft elevation, and 14 switchbacks to the top. It is fairly easy walking, but steeply uphill. Just below the top the trail forks. The left fork curves into the trees to Crater Ice cave. The right fork continues to the top of Big Pryor Mountain. There is a large marker post at the top, an “Unauthorized Trail” sign indicating the end of 4WD route #2088 from the south, and another “Crater Ice Cave Trail” sign.

Extending your hike:

There is a faint two track route heading NW from the top of Big Pryor Mountain. It is not legal for motorized use and thus an inviting hiking route. There is a sign indicating it is an “Unauthorized Trail” for motor vehicles. After 2.2 miles this track intersects another motorized route #2095A.

Another alternative is to follow the ridgeline south along, and parallel to motorized route #2088. Or just wander as you like on this high plateau which we call the “Prairie in the Sky.” Wildflowers can be diverse, abundant and spectacular in season - perhaps late June or early July.

See hike map below.

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