Crater Ice Cave / Big Pryor Mountain

UPDATE (June 2015): There is now a trail sign near the trailhead. Unfortunately it is poorly placed 100 yards from the Tie Flat Rd. (# 2104) where it is hard to see. If you look for it, you can see the sign to the southwest of Tie Flat Rd on the right about 0.1 mile from the Pryor Mountain Rd (#2308) junction. It is too small to read until you walk much closer.

Although some people drive the 100 yards to park at the sign, that violates Forest Service regulations – and damages the landscape. Please park beside Tie Flat Rd (#2104).

Revised 7/31/14

Download printable Crater Ice Cave / Big Pryor Mountain hiking guide.

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 thick forest of Douglas fir. The climb is cool, quiet and secluded. 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 massive 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. Wildflowers can be profuse on the subalpine plateau in late June or early July depending on the season.

Big Pryor Mountain from the East  (Photo by Dick Walton) Big Pryor Mountain from the East (Photo by Dick Walton)
Crater Ice Cave / Big Pryor Mountain Trail Map.  Trailhead on Tie Flat Rd - Yellow Arrow.  0.4 mile Trail Sign - Yellow Diamond.  Crater Ice Cave - Purple Diamond.  Top of Big Pryor Mountain - Purple Triangle.  (<i>Red GPS Track by Jim Reid</i>) Click to Expand - Crater Ice Cave Trail Map

An important trail sign 0.4 miles up the trail has now been moved to a more helpful location. The directions below should get you to the trailhead and past the 0.4 mile point. There is still no sign marking the trailhead on Tie Flat Road. Once found it is a pretty good trail and easy to follow.

This is the only trail in the Pryors designated for hiking by Custer National Forest (CNF). The Pryors Coalition believes CNF needs to improve the trail signing, and publish a hiking guide to this, and other non-motorized routes
in the Pryors.

Getting to the Trailhead:

Tie Flat Rd and sign at junction with Pryor Mountain Rd (#2308). Tie Flat Rd and sign at junction with Pryor Mountain Rd (#2308).
From Bridger MT follow the instructions and map for Pryor Mountain Road, or use the Pryor Mountain Map set.
At 29.7 miles from Highway 310 on Pryor Mountain Road turn right (south) on the two track Tie Flat Rd. #2104. (This is 7.7 miles from the cattle guard where Pryor Mountain Rd. (#2308) enters Custer NF, and 0.6 miles southwest on #2308 from the Crooked Creek Rd. junction.) Follow #2104 for 0.1 mile to a junction with a two track trail to the right (southwest). Route #2104 continues straight ahead without a sign.

Park here. This is the unmarked trailhead. The two-track trail to the right is the trail and is signed “No Motor Vehicles” about 300 ft from the trailhead.

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.

Trail beginning from Tie Flat route #2104.  Deer on trail. Trail beginning from Tie Flat route #2104. Deer on trail.
0.4 mile clearing, trail sign and trail (arrow). 0.4 mile clearing, trail sign and trail (arrow).
A “Crater Ice Cave Trail” sign is visible about 100 feet south (left) on the old road. 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.

Primitive trail paralleling gully. Primitive trail paralleling gully.
Saw cut logs beside primitive trail where it enters trees. Saw cut logs beside primitive trail where it enters trees.

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.

Crater Ice Cave Crater Ice Cave
Inside Crater Ice Cave, HDR photo by Craig Christopherson Inside Crater Ice Cave, HDR photo by Craig Christopherson

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 reaches another motorized route #2095A.

A second alternative is to follow the ridgeline south along, and parallel to motorized route #2088. It is a gentle, slightly down hill walk to Red Pryor Mountain which is a “bump” about 100 ft elevation above the ridge. If you go all the way to Red Pryor Mountain this adds an additional 6 miles (round trip), and 500 ft elevation gain (mostly on the return) to the hike.