Crater Ice Cave / Big Pryor Mountain

This is a short and steep trail from Tie Flat (near the north end of Crooked Creek Road) to the top of Big Pryor Mountain and Crater Ice Cave. In a distance of 1.7 miles (one way) it climbs 1,600 feet up the northeast corner of Big Pryor Mountain. Most of the climb is through a thick forest of large Douglas fir. The climb is cool, quiet and secluded. Look for abundant squirrels and occasional dusky grouse. Black bear have been seen on this trail. Viewpoints are scarce during the climb, but this is more than made up for by the final view from the highest point in the Pryors at 8786 feet elevation. This is 10 feet higher than the top of East Pryor Mountain. From the top there are massive views of 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.

Custer NF has no signs marking either the trailhead or along the trail, making it difficult to find. At a critical spot the trail is invisible to anyone who doesn’t know it is there. The directions below should get you there, and once found it is a pretty good trail and easy to follow. Please tell us if these hike directions work and suggest improvements.

This is the only trail in the Pryors designated for hiking by Custer National Forest (CNF). Unfortunately CNF has no information pamphlets about this or any other hiking opportunities in the Pryors. The Pryors Coalition believes CNF should post signs at the trailhead, do some minimal maintenance on the trail, and publish a hiking guide to this, and other non-motorized routes in the Pryors.

Getting to the Trailhead:

From Bridger Montana follow the driving directions and map for Pryor Mountain Road (#2308). At approximately 29.7 miles from Highway 310 turn right on the two track road signed as 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 before the Crooked Creek Rd. junction.) Follow #2104 for about 0.1 mile to a junction with another two track road to the right – signed #21041. Route #2104 continues straight ahead without a sign.

Route #21041 is not legal for motorized use although there is no sign indicating that restriction. This junction is the “trailhead”, although there is no sign to indicate that fact either. Park here. Please do not drive up #21041.

The Trail:

Walk up route #21041 for 0.4 miles. At first it is in open grassland, but soon enters the trees. At 0.4 miles, and 300 ft elevation gain, the track arrives at a small flat opening in the trees. This is the end of #21041. There are two signed motor-legal routes to the right (north) – #2002A and #2002A1 and an unsigned track to the left (not motor-legal). None of these is the hiking trail.

This is the most confusing point on the hike and could be considered a second “trailhead.” There is no sign indicating that there is a hiking trail here, and there is no visible trail (as of 9/22/11).

  At the top end of #21041, follow the left unsigned track for about 100 ft., then turn right (uphill) into the bottom of a small gully. Push through the brush for about 40 feet up the bottom of the gully. Look for a 3 ft. (approx.) boulder and a couple sawed tree stumps on the left side of the gully. At that point climb up the right (north) side of the gully and push through a grove of several small trees. Here, on the side of the gully, look for a trail paralleling the gully and close to its edge. This trail is like a game trail – not constructed. You should find this game trail less than 100 feet from where you entered the bottom of the gully.

Follow the game trail uphill along the gully edge for about 200 ft. through open grass and low brush (snowberry and Oregon grape). At the point you enter thick timber, you should come to a Douglas fir tree, approximately 12 in. diameter, fallen perpendicularly across the trail. It may appear that there is no more trail. Scramble over the log and turn right along it. You should quickly find that you are on a constructed trail, which is flat even though it contours around the hillside. Congratulations, you have found the trail.

From this point the trail it is fairly obvious and is usually fairly easy walking as it switchbacks up the steep slope through the timber. However on the bottom section there are a number of trees down across the trail which must be scrambled over or under. Higher up the trail switchbacks up the hill with a good grade and trail bed. Occasionally it crosses what appears to be an earlier version of the trail. Follow the most prominent trail.

It is about 1 ¼ mile, and 1,300 ft elevation gain, from the top end of #21041 to the top of Big Pryor. Since there are no trail signs, and the top end of the trail is not obvious from above, be sure to notice where you come out of the trees so you can retrace your route back down.

Crater Ice Cave is in the trees on the steep slope just below the top of Big Pryor Mountain and to the left as you go up the trail. There is a marker at the top of Big Pryor Mountain, and an “Unauthorized Trail” sign indicating the end of 4WD route #2088 from the south.

Extending your hike:

There is a faint two track route heading NW from the top of Big Pryor Mountain which is closed to motorized use. As of August 2011 there was a sign indicating it is an “Unauthorized Trail” for motor vehicles. After 2.2 miles this track reaches 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.

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