Glenns Lake Trail

Glenns Lake Trail is a long wilderness route from the Belly River trailhead at Chief Mountain Customs to the Head campsite on Glenns Lake. The one-way walk is about 12.7 miles, so the full return is about 25.3 miles. Treat it as an overnight trip, not a casual day hike. The Head is the fullest lake destination; the Foot campsite is a shorter turnaround about 10.2 miles from the start. Continuing from Foot to Head adds roughly 2.5 miles each way and the steepest climb.

The first two miles descend about 700 feet. After that, the trail follows the Belly River valley and gains only about 250 feet over the next 6.7 miles to Cosley Lake. Near the junction, a suspension bridge crosses the Belly River, then the path climbs over a ridge toward Cosley. That easy-looking start has a cost on the way back: you finish by climbing those first two miles toward Chief Mountain.

Cosley Lake is about 8.7 miles from the trailhead, with its campground close to shore. From the water, Pyramid Peak, Mount Kipp and Cathedral Peak frame the valley, with Shepherd Glacier visible on Cathedral Mountain. When the surface is still, the peaks and their reflections make the shoreline a worthwhile stop. A short spur leads to Gros Ventre Falls. The separate Bear Mountain spur adds about 1.7 miles and nearly 1,400 feet of climbing, so it is a substantial extra trip and is not included in this route.

After skirting Cosley Lake, the trail crosses an alluvial fan and reaches Glenns Lake Foot at about mile 10.2. The last stretch to Head climbs steeply through dense forest for roughly four kilometres. Views are limited while you climb, but Head is the upper-lake destination and the reason to keep going if you have the time and legs. If that steep finish is too much, Foot is a real, shorter endpoint rather than a failed version of the hike.