Jupiter Traverse

The Jupiter Traverse is a serious ski-mountaineering linkup above Rogers Pass in Glacier National Park, crossing the three summits of Mount Jupiter—Castor, Pollux and Leda—on a long, exposed alpine ridge. Most parties start from the Illecillewaet parking area and skin up the Asulkan drainage past the Mousetrap to the Asulkan Glacier, then climb to Sapphire Col and the small Sapphire Col Hut before committing to the ridge.

From Sapphire Col the route becomes full-value: bootpacks and short skis along a narrow, corniced crest with big exposure on both sides and complex micro-terrain between the three peaks. The standard finish drops the Thorington Route, a steep glaciated face with a large convex roll and crevasse hazard that demands stable conditions, strong group management and solid steep-skiing skills. A more conservative out-and-back or continuation toward Asulkan Pass avoids the Thorington but still keeps you in serious alpine terrain.

Expect heavily wind-affected snow, overhead cornice hazard and frequent wind slabs along the ridge, with crevasses and serac debris on the glacier approaches and exits. This is not an entry-level Rogers Pass tour: teams should be comfortable with glacier travel, booting and skiing in no-fall terrain, and making conservative calls when visibility or stability deteriorate. The traverse lies inside Glacier National Park’s Winter Permit System; check daily area openings, avalanche bulletins and any closures before leaving the lot, and carry the required permits and maps.

For current access, winter permits and avalanche information, see Parks Canada’s Rogers Pass ski touring page: parks.canada.ca.