Chasm Lake is located 4.2 miles from the Longs Peak Trailhead in Rocky Mountain National Park. It fills a deep cirque carved from the base of Mt Meeker (13,911'), Longs Peak (14,259') and Mount Lady Washington (13,281'). Longs Peak's 'Diamond' rises 2456' above this striking alpine lake.

The trail clears treeline after 2 miles with rangy views across the tundra and down the Roaring Fork drainage to Estes Cone and the Twin Sisters

The East Longs Peak Trail splits off the Chasm Lake route and arcs around the base of Mount Lady Washington to Granite Pass and the Boulderfield

Alpine tundra grasses include the Alpine Blue Grass, Skyline Blue Grass, Spike Trisetum, Tufted Hair Grass, Spreading Wheatgrass, Kobresia and Pyrennian Sedge

There have been at least 6 major glaciations in the last 700,000 years, some of which lasted tens of thousands of years

Phototropic enzymes in 'Old Man of the Mountain' flowers direct the flower head toward the sun and follow it as it moves across the sky

Roaring Fork creek flows out of Chasm Lake and joins Cabin Creek just east of HWY 7

The Longs Peak Keyhole was formed by freeze-thaw cycles between vertical rock slabs, and glacial ice atop the rock acting as a wedge to pry rock loose

The trail crosses the top of Roaring Fork with good views east of the Twin Sisters massif

All glaciers in Rocky Mountain National Park are cirque glaciers, which are comparatively small glaciers that fill a bowl-shaped basin at the head of a valley

When wet soil freezes it expands and pushes surface-level rocks up in a process called frost heaving

Follow me! Cairns mark the short but tricky scramble into the lake basin

Steep snowfields can persist well into summer and may be impassable without additional traction

Travel eases briefly across a grassy bench before the final steep scramble to the lake

Moss campion is an alpine cushion plant that grows low to the ground in tight mounds with flower buds that hide between leaves until popping out at once for a brief time in the summer

The Longs Peak massif was likely a single rounded summit before glacial movements carved out distinct summits

The Chasm Lake Trail heads up a narrow gorge past the Longs Peak split with good views over Peacock Pool and Columbine Falls

Plants of the tundra produce pigments capable of converting the sun's light rays into heat

Columbine are a notoriously hardy flower that can tolerate extreme weather and depleted soil