Hiking the Chasm Lake Trail in the Rockies

Updated November 25, 2024 02:32PM

The Chasm Lake Trail in Rocky Mountain National Park shares a trailhead with the park’s only fourteener, Long’s Peak. The hike is renowned for its impressive views of Long Peak’s 1,000-foot Diamond Face towering above the glacial waters of Chasm Lake. Be prepared for a challenging Class II scramble as you near the lake and high-elevation hiking.

Trail Facts

The Route

The Chasm Lake Trail starts at the Longs Peak trailhead and follows a challenging yet beautiful route to the shores of Chasm Lake.

From the Longs Peak trailhead, follow a wide path that climbs steadily through ponderosa pine. This trailhead is more remote than others in the national park, but as the gateway to the park’s only fourteener, it can be a veritable highway for hikers in July and August.

Switchback upward, occasionally edging mountain streams, until you reach treeline just past mile two. From here, the trail heads across a wide, rocky basin toward Longs Peak, which is now in view. Crest a small ridge at mile 3.2—this is a great place to drop your pack for a quick snack, photo op, and use the privy, if necessary. (Why not? It has no roof and a great view of Longs’ 1,000-foot Diamond Face.)

From here, edge left down into the valley that leads up to the Diamond. In early to mid-summer, cross a patch of snow on the descent to Columbine-lined stream crossings in front of a patrol cabin.

South of the cabin, scout out cairns on the rock above marking the path. In five or ten minutes, summit the class II scramble to impressive views of the Diamond and icy Chasm Lake at its base. Shoo away aggressive marmots and chipmunks as you search for climbers on the Diamond and Ship’s Prow, to the left.

When you’ve taken in your fill of scenery, turn back and head to the trailhead the same way you came.