I recently had the opportunity to summit Bighorn Peak and ski Schoolbus Couloir off the east face. A partner and I had an attempt mid-June of this year, but we were hindered by mediocre snow and weather conditions. Our June attempt included access via Circle Park to the east. At that time, you could drive to the trailhead and hike several miles before hitting snowdrifts that were continuous enough to start skinning- this was near Rainy Lake. Travel past Lame Deer Lake is much easier in early summer via skinning- later in the summer the famously horrendous boulder fields are exposed. Although you could climb directly up the couloir, this line has huge exposure, especially from cornice drops and rockfall off the cliff band on the south flank of the line. The top 300-400 ft. of the line is very steep, and climbing on rope would be requisite. This line has seen few successful ski descents because a massive cornice rims the entire top of the couloir. Except in late season, there is no way into the line without skiing on rappel over the likely touchy cornice, or airing 20-30 ft. off it onto a very steep (60 degree plus), fairly narrow chute. This summer saw the line hold out longer than ususal, due to double average snowfall last winter. On August 18, I accessed the summit of Bighorn Peak via boulder fields up from Lost Twin Lakes, to the northwest of the peak. This route is as good as any for those just wanting to summit, but is definitely not the best route for a summit scramble, then ski descent. I would think via Firehole Lakes would save a lot of energy. I downclimbed to just below the cornice via a rock chimney on the south side of the couloir, then skied from there. The snow was deeply runneled. This combined with the steepness of the upper pitch made for survival skiing. The middle of the line saw snowpack laced with small rockfall debris. By mid- August, most of the apron is melted out, and although you can piece your way down, a continuous ski to the lake is not possible in late summer. This beast of a ski mountaineering line is a challenge- when snow conditions are good, the cornice atop still impedes access. By the time the cornice is easier to pass, the snow conditions are pretty well decimated. However, it is one of the longest high altitude ski lines in the Bighorns, and certainly the most dramatic. If future climbers are crazy enough to try to ski Schoolbus Couloir, I would recommend attempting in mid to late July- after most cornice sluffing has ended, but snow conditions are still good. At that time, most sane people would want to rappel into the top of the line.
I think I would do a double take if I saw skis on the trail in August. But, thanks for sharing such an interesting take on Bighorn Peak. It makes me disappointed that I missed such an interesting climbing season in the Big Horns.