This is a fantastic high-alpine running experience.
The Arapaho Glacier Trail #905 leads northward from the main trailhead (located before entering the Rainbow Lakes
Campground) and crosses into the Indian Peaks Wilderness. Climbing through the woods for about two miles, the trail exits onto the open tundra with a fine view into the City of Boulder Watershed. As posted, this area is private. Do not trespass.
After additional switchbacks, the Arapaho Glacier Trail crosses to the south side of the ridge. At the highest point on the trail is a spectacular overlook of the Arapaho Glacier, South Arapaho (13,397 feet), and North Arapaho (13,502 feet) Peaks.
Although no official trail exists, it is possible to ascend South and North Arapaho Peaks by following the ridge above the glacier. The climb to South Arapaho Peak
is straightforward rock hopping. From South to North Arapaho Peak, scrambling is necessary. Technical equipment is not required but the narrow ridge is steep and rocky. Use caution.
The Arapaho Glacier Trail descends 1,300 feet down a series of switchbacks to intersect the Arapaho Pass Trail
#904 at the Fourth of July Mine. Arapaho Pass is 1.2 miles farther west.