Ypsilon Lake Trail

Overview

A classic Mummy Range outing with fewer crowds than the park’s headliners, this out-and-back climbs steadily from the Lawn Lake corridor to a serene, timberline-fringed basin. Expect roughly 9.4 miles total with about 2,200–3,000 feet of gain. Most of the work is on the way up; many hikers report the ascent taking the lion’s share of time, with a quicker cruise back down.

What You’ll See

Early in the day, brief openings give peekaboo looks back toward Longs Peak’s Diamond Face. Much of the middle miles are forested—open lodgepole with enough spacing to create that cool “moving parallax” as you climb—before the trail drops to Chipmunk Lake and then Ypsilon Lake. The lakes are the payoff: glassy water, dark timber, and cliffs hinting at the high cirques above. A short path at the inlet reveals a pretty waterfall. Ambitious hikers sometimes continue beyond the lake on a steep, unmaintained scramble to the Spectacle Lakes for true alpine drama; it’s gorgeous but requires solid route-finding and comfort on steep, rocky terrain.

Trail Character and Difficulty

Call it moderate to moderately strenuous: a consistent grade of roughly 500 feet per mile, generally good footing, and a final short descent to the lake (remember, you’ll climb back out). If you push to the Spectacle Lakes, difficulty spikes due to steep scrambling.

Geology and Setting

You’ll travel above the Roaring River, whose corridor was dramatically reshaped by the 1982 Lawn Lake dam failure, creating the Alluvial Fan. The whole area is a lesson in ice and water—glacially carved basins and cirques ring the upper valley, with high walls and peaks enclosing the headwaters.

Crowd Level and Vibe

Compared to marquee lakes, this one stays relatively quiet—especially after the first couple of miles. Some hikers find Ypsilon Lake itself a touch underwhelming versus the park’s flashier gems; others love the solitude, the inlet falls, and the optional scramble for big alpine vistas.

Best Time to Hike

Start early. You’ll get cooler temps, the best chance at sunrise glow on Longs, and a safer window before summer thunderstorms. Snow and ice can linger near and above treeline into early summer; shoulder seasons often call for traction. Midweek mornings are the sweet spot for quiet.

Tips

• Save a few minutes to explore the lake’s inlet for the waterfall.
• If you plan to scramble above the lake, bring a map, be comfortable with off-trail navigation, and turn around if weather builds.
• The main corridor is well maintained and crosses a rebuilt footbridge over the Roaring River.