Chasm Lake Hike Overview

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Chasm Lake Hike Overview

Sitting pretty in a deep cirque in the shadows of Mount Lady Washington and Longs Peak in Rocky Mountain National Park, Chasm Lake is one of the best hikes in the park. The Diamond (east-facing wall of Longs Peak) rises more than 2,400 over the deep blue lake. Look south and you can see 13,911-foot Mount Meeker. Ready to tackle it? Here’s what you need to know about the Chasm Lake hike.

Where Is Chasm Lake?
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Chasm Lake is in Rocky Mountain National Park. The strenuous, 8.6-mile hike begins from the East Longs Peak Trailhead and takes you to an elevation of 2,456 feet. To reach it, drive 8.9 miles south from Estes Park on Colorado Highway. Take the turnoff for the Longs Peak Ranger Station. Aim to arrive as early as possible to ensure a parking spot, beat the crowds and hopefully avoid exposure to afternoon thunderstorms.

What Is the Chasm Lake Hike Like?
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Hike for 2.2 miles from the Longs Peak Trailhead, then emerge from the forest into a subalpine zone at about 10,750 feet in elevation. Notice the krummholz (German for “twisted wood”) – the stunted, irregular trees found in these transition zone. Pass the spur trail to Battle Mountain Backcountry Campsite and ascend Mills Moraine. At about 3.4 miles (11,540-foot elevation), you’ll arrive at the junction for Chasm Lake Trail. Look west and you’ll see the dominating outline of 13,281-foot Mount Lady Washington.


Follow the Chasm Lake Trail southwest along a gorge, from which you can see Peacock Pool and Columbine Falls. Walk through the basin, then start to climb the headwall that forms Chasm Lake. Follow the cairns as you see fit – there are several different routes through this section. You can access some of the shoreline with some rock scrambling, if you wish. Want to go farther? Continue on to Battle Mountain, the Boulder Field or the Keyhole.

What Are Some Other Good Hikes in Rocky Mountain National Park?
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Other favorites include Lake Haiyaha, which begins from the Bear Lake Trailhead. You can do this one as an out-and-back hike or a loop. The one-way loop will visit Nymph Lake, Dream Lake, Mills Lake and the Loch, as well as Glacier Gorge and Alberta Falls. When you reach Lake Haiyaha, drink in the magnificent scenery, with 12,486-foot Otis Peak and 12,713-foot Hallett Peak in your sights. Chaos Canyon lies between the two mountains.


The Twin Sisters Peak Trail is another favorite. Hop onto the trail near Lily Lake. Drive 6.3 miles south from Estes Park on Colorado Highway 7, then turn left at the Lily Lake Visitor Center (not in operation any longer). Continue up the gravel road to the parking area. This is an easier hike than others in the area and a good warm-up to get acclimated to the elevation before taking on the Keyhole on Longs Peak or Hallett Peak in the Bear Lake area.


If you’re hoping to summit Longs Peak, the Keyhole is considered the easiest route to the peak. All told, it’s a 14.5-mile roundtrip to the top, with a more than 5,000-foot elevation gain and a class-3 scramble near the top.

When Is the Best Time to Hike Chasm Lake?
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To ensure that the snow is mostly melted and the hiking trails are accessible, plan to visit Rocky Mountain National Park between June and September. No matter where you are hiking in the park, it’s a good idea to start as early in the morning as possible so as to avoid unpredictable afternoon thunderstorms. That being said, the national park is open every day, all year, so you can also visit for snowshoeing or cross-country skiing between October and May.


If there is still snow on the trail, be cautious and carry trekking poles and microspikes. The snow on the trail is especially prone to avalanches in winter and early spring. If you’re tackling the Chasm Lake Trail when there is still a fair amount of snow, consider taking an avalanche awareness class. Always check in with the park rangers for the local conditions and forecast.

Can I Get Rocky Mountain Views Without Hiking?

Yes! Drive the Old Fall River Road, which was the first auto route in Rocky Mountain National Park back in 1920. This primarily dirt, one-way uphill route, full of switchbacks, is 11 miles long and demands a slow, cautious pace. You’ll start at Horseshoe Park and make your way to Fall River Pass at 11,796 feet above sea level. Pass Willow Park – look for elk! – then enter the alpine tundra area, where you’ll see the Fall River Cirque. Traverse the headwall of this natural amphitheater before joining up with the paved Trail Ridge Road near the Alpine Visitor Center. Continue on this equally appealing route east to Estes Park.

What Should I Bring When Hiking Chasm Lake?

When hiking Chasm Lake, you’ll be above the tree line for a significant portion of the time. Pack appropriate clothing – check the weather forecast 24 hours before your hike and the morning of your hike. In addition to the items below, bring extra food and water and perhaps some binoculars to watch rock climbers attempt the Diamond of Longs Peak.


Your hiking checklist should include:


Backpack appropriate for hiking

Weather-appropriate clothing (layers!)

Hiking boots or shoes

Food and water (bring extra)

A map and compass

First-aid kit


Headlamp or flashlight

Sun protection


Shelter (emergency space blanket will suffice)

Where Should I Stay If I’m Hiking Chasm Lake?

Consider staying in Estes Park, where accommodation options include a historic hotel, lodges and inns, vacation homes, condos and cozy cabins. You’re only about a 20-minute drive from the trailhead here. At the end of the day, you can fuel your hiking appetite at any number of Estes Park restaurants, grab a local beer, do a little shopping or even visit an art gallery or glassblowing studio.

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