OverviewSunbeam Peak is the 11th highest mountain in the Wind River Range and the 12th highest in Wyoming. Sunbeam consists of a 2 mile long NW to SE trending ridge system, most of which comprises the E wall of the uppermost section of Dinwoody Glacier. The highest point is in the center of this trend. The NW section of the ridge extends between Dinwoody Glacier and Heap Steep Glacier and contains three pinnacles: East Sentinel, Heap Steep and Speck. To the east, a boomerang-shaped ridge descends gently from the summit block to Blaurock Pass. To the SW from the summit, a steeper gendarmed ridge drops to remote and seldom used Backpackers Pass (which is actually a col). To the SE, a large, flying buttress extends from near the summit into the valley below Helen Glacier. Routes of all nature have been established.
ApproachesThe standard approach is via the Glacier Trail from the Torrey lakes trailhead. 4 miles east of Dubois, turn south from highway 26/287 and follow the recently improved dirt road (FS #411; passable in cars) eight miles past Trail Lake Ranch to its end. The Glacier Trail is then taken for approximately 21 miles to the Dinwoody moraine. The area can also be reached from the Elkhart Park trailhead via the route over Bonney Pass. This entails a trek of a similar distance but adds the high crossing of the divide.
Seasonal ConditionsSummer season in the Wind Rivers is generally July-September with snow lingering on the higher trails into July. A snow storm is traditional between the last week of August and the second week of September. This is normally followed by a dry period with crisp temperatures for 1-4 weeks. On glacier routes, crevasses are hidden in June and begin opening sometime in July. Because the Trail Lake/Torrey trailhead is below 8000', on the dry side of the range (the glaciers above absorb the majority of the storms, causing a rain shadow near Dubois), the trailhead can surprisingly be reached almost year round; the exception being during heavy spring storms. The downside for ski approaches is that several miles must often be hiked before significant snow is reached. An area webcam depicts current conditions. The approach can be heavy with mosquitos June thru July. Water must be carried the first 10 miles of the Glacier Trail.
Guides & OutfittersSeveral Dubois Outfitters can provide packhorses, guides, or equipment drops to the base of the Dinwoody Glaciers. Sunbeam is guided by Jackson Hole Mountain Guides and Exum. It is also made available to participants in NOLS courses.
RegulationsThe west side approach is managed by the Bridger Wilderness and National Forest. The peak is in the Fitzpatrick Wilderness of Shoshone National Forest. Wilderness regulations apply for camp locations, group size, campfire restrictions and ethics. There are bear requirements for food storage. Grizzlies have migrated back to this part of the range in the last decade; appropriate preparations are advised. Minimum-impact camping and travel ethics are increasingly important along the Dinwoody and at Double Lakes. Camping stoves and water filtration are required. The Trail Lake trailhead has an undeveloped campground. The Elkhart Park trailhead has developed sites.
- Sunbeam was named by original Grand Teton National Park ranger Phil Smith in 1946. It had been climbed by a party including Don Grant and Pauline Clare in 1938.
- Blaurock Pass is named for pioneer Rockies mountaineer Carl Blaurock and connects this peak with Mount Febbas.
- It's infrequented summit may still have its original register.
- The Fitzpatrick Wilderness is named for famed mountain man Tom "Broken Hand" Fitzpatrick.