Chasm Lake Hike Route Guide

Route Description for Chasm Lake Hike

Chasm Lake Hike
Don’t let the mileage deceive you – the Chasm Lake hike is a demanding alpine trail that begins at 2,743 m in elevation and feels harder than it first appears. The effort is well rewarded, with close-up views of the Diamond Face of Longs Peak towering above Chasm Lake, seasonal wildflowers including columbine in early summer, and views of Columbine Falls flowing toward Peacock Pond.

Before starting the Chasm Lake hike, stop at the Longs Peak trailhead information board to check the day’s weather report. Conditions in Rocky Mountain National Park can change quickly, and exposure increases as you gain elevation on the Chasm Lake route.

Begin the Chasm Lake hike by following the trail west from the Ranger Station. This is the same initial route used by hikers heading for the Longs Peak summit, so expect steady foot traffic early on.

The Chasm Lake trail starts gradually before becoming increasingly steep. At 0.8 km, stay left on the main trail at the signed junction. You’ll remain in forest for more than 3.2 km, catching brief views of Longs Peak through the trees. At 2.7 km, you’ll reach the first footbridge, which is usually dry but may carry water during snowmelt or after heavy rain.

At 3.2 km, you’ll cross a longer bridge over a year-round stream and small cascade. Shortly afterward, the Chasm Lake hike emerges above treeline into alpine tundra. Vegetation becomes sparse, the trail rockier, and views more expansive. Battle Mountain appears to the right, with a spur trail leading to the Battle Mountain campground. Stay on the main route toward Chasm Lake.

At approximately 5.5 km, you’ll reach a major junction. Straight ahead leads to Chasm Lake, while the right-hand trail continues toward the Longs Peak Keyhole Route. A toilet is located to the left. Continue straight for 1.2 km toward Chasm Lake.

The trail briefly descends for about 0.8 km, opening up dramatic views of the Diamond Face of Longs Peak directly ahead, with Mount Meeker to the left and Mount Lady Washington to the right. Depending on the season, snowfields may persist here. Use caution and assist balance with poles or hands if crossing snow. Snow is often gone by late August but can return early in autumn.

The Chasm Lake trail then climbs again toward the top of Columbine Falls. Carefully follow the established path over large boulders and sensitive terrain near the flowing water. The route winds through a marshy area, crossing the stream several times before reaching a rocky section. Another small waterfall can often be seen cascading down the cliff to the right.

A sign marks the final ascent to Chasm Lake. Scramble up approximately 15 m of rock, following cairns or choosing the easiest line. This short scramble brings you to the rim of Chasm Lake.

At the top, Chasm Lake comes fully into view, sitting beneath the sheer Diamond Face of Longs Peak. This is an excellent place to rest, take photos, and watch climbers high above on the wall.

To return from Chasm Lake, retrace the same route back to the trailhead.

Hiking Trail Highlights

Chasm Lake

The centerpiece of the Chasm Lake hike is Chasm Lake itself, a striking glacial tarn set in a deep cirque at the base of Longs Peak, Mount Meeker, and Mount Lady Washington. Steep scree slopes and rocky terrain surround the basin, with portions of permanent snowfields such as the Mills Glacier visible above.

Fed by glacial meltwater, Chasm Lake often displays a vivid turquoise color under clear light. The contrast between the bright water and the dark, rugged peaks makes this one of the most dramatic lakes in Rocky Mountain National Park. Swimming is possible but extremely cold even at the height of summer.

Longs Peak Views

Longs Peak is the highest mountain in Rocky Mountain National Park, rising to 4,346 m above sea level. As one of Colorado’s iconic fourteeners, it attracts climbers from around the world. The Chasm Lake hike offers an up-close view of Longs Peak’s Diamond Face without committing to the full summit climb.

Named after explorer Stephen Harriman Long, the mountain is especially famous for the Diamond, a 270 m sheer granite wall that forms a classic alpine climbing route. From Chasm Lake, the scale and steepness of the Diamond Face are particularly striking.

Waterfalls Along the Chasm Lake Trail

Columbine Falls is a notable feature along the Chasm Lake trail, flowing strongly during spring snowmelt and glowing with warm light at sunrise. In winter, the falls freeze solid and become a popular ice climbing location, while spring runoff creates an impressive cascade.

What’s New at Chasm Lake Hike in 2026

There are no major changes to access, route conditions, or regulations for the Chasm Lake hike in 2026. Seasonal snowfields, alpine exposure, and rapidly changing weather remain key considerations. Hikers should continue to start early and monitor weather forecasts before setting out.

Planning Your Chasm Lake Hike

Parking and permits

The Chasm Lake hike begins at the Longs Peak Trailhead, where timed-entry permits or park access regulations may apply depending on the season. Arriving early helps secure parking and reduces exposure to afternoon storms.

Best time to hike Chasm Lake

Late June through September is generally the best window for hiking to Chasm Lake, though snow can linger into midsummer. Early starts are recommended year-round.

Safety considerations

The Chasm Lake hike is strenuous and exposed. Carry extra layers, water, food, and be prepared to turn back if weather deteriorates.

Families and dogs

Due to elevation gain, rocky terrain, and snowfields, the Chasm Lake hike is best suited to experienced hikers. Dogs are not allowed on trails in Rocky Mountain National Park.

Frequently Asked Questions About Chasm Lake

How long is the Chasm Lake hike?

The Chasm Lake hike is approximately 8.4 miles round trip.

How difficult is the Chasm Lake hike?

Chasm Lake is considered a difficult hike due to elevation gain, altitude, and exposure above treeline.

Is Chasm Lake worth it?

Yes, many hikers consider Chasm Lake one of the most scenic destinations in Rocky Mountain National Park thanks to its dramatic setting beneath Longs Peak.

Guided Hiking Trips in the United States

If you enjoy challenging alpine hikes like Chasm Lake, you may also be interested in guided hiking tours in the United States that explore national parks and mountain regions.

Want to find more amazing hikes in Rocky Mountain National Park? Check out Lake Haiyaha hike or the Sky Pond and Lake of Glass hike.