Chasm Lake Is the Best Day Hike Near Denver

The first time I hiked Chasm Lake, I was convinced I'd fallen into the eponymous chasm beside the trail, died, and gone to heaven.

It's hard to describe how beautiful this day hike is. To start with, picture ribbon-like waterfalls flowing down hundreds of feet. And when you finally reach your destination, you might just find the diamond-shaped summit of Longs Peak reflected in the water.

I almost included Chasm Lake in my last post about the best all-season hikes in Rocky Mountain National Park. But I removed it at the last minute, because the final approach can be quite hazardous under snow. And truth be told, it's under snow for much of the year. (I'll share some tips for this part in a minute.)

[Photo credit: CC image courtesy of Dustin Gaffke via Flickr]

2020 Coronavirus update

As of this writing (June 7, 2020), Rocky Mountain National Park was open to a limited number of visitors. To enter the park, you must make a reservation by purchasing a ticket at recreation.gov. Your ticket allows you to enter the park at a designated time.

The situation is evolving rapidly, so visit the Rocky Mountain National Park website for the latest info.

More on the timed-entry system (scroll down).

Some Chasm Lake hike details:

• Trailhead: Longs Peak

• Round Trip Distance: 8.4 mi.

• Elevation Gain: 2,456'

• Max Elevation: 11,823'

• Winter Skill Level: Advanced (ice ax recommended)

Hike Highlights

The hike to Chasm Lake is bursting with superlatives. A few awesome things to look for:

• Krummholz. As you emerge above tree line, look for forests of twisted dwarf trees. These poor guys have been warped by a lifetime of screaming wind, frozen soil, and scant rainfall. "Flagging" of the branches indicates the prevalent wind direction.

• Cairns. On some trails, it's tough to follow these rocky trail markers. But the ones on the popular East Longs Peak Trial are massive ... and getting bigger every year.

• The outdoor privy at the junction. Just before the turnoff to Chasm Lake, pause for a bathroom break at this open air toilet. Talk about a pee with a view!

• Columbine Falls and Peacock Pool. As you approach Chasm Lake, you'll be hiking above, well, a chasm. Pause to enjoy the gorgeous ribbons of snowmelt cascading down the mountain into this gash. The tallest, Columbine Falls, plunges for over 200 feet into colorful Peacock Pool

Bonus: Click the button below to download a free, printable topo map of the Chasm Lake hike.

Valerie beside on the rocky shores of Chasm Lake with Longs Peak Diamond face in the background

About Longs Peak

One reason to hike Chasm Lake hike is to get up close and personal with the monarch of Rocky Mountain National Park.

Rising to an elevation of 14,259', Longs Peak is the northernmost of the Colorado 14ers and the only one located in RMNP. From Chasm Lake, you'll have a perfect view of The Diamond, the peak's elegant summit block.

About 30,000 people attempt the climb Longs Peak ever year. Popular routes include:

• The Keyhole. This is the "easiest" route on the peak. But with 14.5 mi. round trip distance, over 5,000' of elevation gain, and a class 3 scramble near the top, it's actually one of the harder 14er routes!

• The Loft. Another scrambling route that ascends a couloir (gully) near Chasm Lake.

• The Diamond and the East Face. Yes, people climb it! The routes are for experts only, requiring a thousand feet of Class 5.10–5.13 climbing. Many ascents involve an overnight stay.

An average of two people die climbing Longs Peak every year, most of them on the Keyhole route. The peak's popularity and accessibility contribute to its relatively high fatality rate.

Chasm Lake Hiking Tips

• The entire hike is located in Rocky Mountain National Park. Camp only in designated areas and leave your pets at home.

• Get a super-early start! Afternoon thunderstorms represent one of the biggest dangers in the park, especially in spring and summer. Also, the Longs Peak Trailhead parking lot fills up fast in summer and on weekends. Download my tip sheet on how to survive the summer crowds at Rocky Mountain National Park.

• The Chasm Lake hike takes you above tree line for an extended time. Check the weather forecast 24 hours before your hike and also before your leave your house or hotel. If storms are forecast, consider leaving earlier or postponing your hike to another day.

• This hike is a true backcountry adventure. Take extra food, water, and basic survival gear. For more on packing for a day hike, see this post. Binoculars can also be fun; you may have a chance to watch climbers on the diamond.

Sarah on the shores of Chasm Lake in the fall

Extra Tips for Snowy Conditions

The Chasm Lake Trail is usually free of snow from mid-July onward. However, the rate of snow melt varies greatly from year to year. Before attempting the hike, it's a good idea to check conditions on the Rocky Mountain National Park website. (Scroll down for the Chasm Lake report.)

Crossing the snow slope can be treacherous. A misstep could send you into an uncontrolled slide into the rocks below. Some hikers pick their way across with no more protection than their poles. I highly recommend bringing an ice ax and knowing how to use it to self belay and self arrest. You should also protect yourself by wearing solid foot traction like Kahtoola microspikes.

The snow slope across the trail is also prone to avalanches. These are especially dangerous in winter and early spring. However, even a small wet slide in the warmer months could knock you off your feet and cause a dangerous fall.

Before heading into avalanche territory, it's absolutely essential to educate yourself. Take an avalanche awareness seminar — or better yet, a field course like AIARE 1. The Colorado Avalanche Information Center (CAIC) is also an excellent source of education and information. And of course, the RMNP rangers can provide the most accurate local forecast.

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So there you have it. A local’s guide to the Chasm Lake Hike in RMNP.

Have you hiked to Chasm Lake? If so, comment to share your tips!

Originally published Oct. 17, 2017. Updated June 7, 2020 to add additional coronavirus info.