Ypsilon Lake

Ypsilon Lake is a stunning alpine destination inside Rocky Mountain National Park in Larimer County, Colorado, where a challenging 4.5-mile hike rewards with jaw-dropping waterfalls, mountain reflections, and a basin framed by some of the park's most dramatic peaks. Starting from the Lawn Lake Trailhead off Old Fall River Road, the trail gains roughly 2,300 feet of elevation, with most of the climb packed into the second half beyond the Roaring River crossing. This is a hike that earns its views, and hikers who make the push consistently rank it among the best lake trails in RMNP.

The trail to Ypsilon Lake passes through dense forest canopy that provides welcome shade during the steep ascent. The Roaring River section is a highlight on its own, with cascading water and rock formations that stop hikers mid-stride. As you gain elevation, Chipmunk Lake appears along the route and offers panoramic views that some visitors consider even more impressive than the final destination. The lake itself sits in a high cirque beneath Ypsilon Mountain, where waterfalls tumble down the surrounding cliffs and the still water mirrors the peaks above on calm mornings.

Seasonal timing significantly affects the Ypsilon Lake experience. Late summer, from July through September, delivers the most accessible conditions with dry trails and flowing waterfalls fed by remaining snowmelt. Early morning starts between 6 and 9 AM are strongly recommended to avoid afternoon thunderstorms common at this elevation and to secure parking at the popular Lawn Lake Trailhead. October visits bring fall color and thinner crowds, though temperatures drop quickly and daylight hours shrink, making an early start even more important.

Winter and early spring transform the hike into a serious backcountry undertaking. Compacted snow creates slippery conditions on exposed sections near Chipmunk Lake, and postholing through deep snow is common above the river crossing. Snowshoes or microspikes are essential gear from November through May. The narrow, cliff-adjacent trail segments demand caution in icy conditions.

Ypsilon Lake is not a beginner hike. The sustained elevation gain, high altitude, and length make it a solidly moderate-to-difficult outing that typically takes four hours up and two hours down. Hikers should carry plenty of water, layers for rapidly changing mountain weather, and a headlamp as insurance against a late return. A valid Rocky Mountain National Park timed-entry reservation is required during peak season, adding a planning step that helps manage trail congestion at this deservedly popular destination.