After a steady ascent through whitebark pine and fir forest, the trail reaches alpine tundra, a wind-scoured world of stunted trees and briefly blooming wildflowers. The steep slopes and low groundcover provide ideal habitat for bighorn sheep, marmots, and pikas. Grizzly bears are especially active in late summer and fall, and bear activity often closes trails in this area. Above treeline, the mountain seems to make its own weather, with storms appearing without warning, temperatures plunging, and snow possible in any month of the year.