Julie United States 11 Comments

Chasm Lake is one of the most spectacular lakes in Rocky Mountain National Park. For the first part of the hike, you will walk the same trail as hikers on their way to Longs Peak, the highest point in the park. Once the trail splits, the hike gets a little easier and you are treated to breathtaking views of Longs Peak, Columbine Falls, and Peacock Pond. After one final short and strenuous climb you will be standing at Chasm Lake.

The hike to Chasm Lake is challenging but it rewards you for your effort. If you have plans to spend several days in Rocky Mountain National Park and you are a hiker, this is one of the best trails to put on your to-do list.

Chasm Lake Hiking Stats

Distance: 8.2 miles out-and-back
Starting Elevation: 9,400 feet 
Highest Elevation (Chasm Lake): 11,800 feet
Total Ascent: 2,700 feet
Difficulty: Strenuous
Length of Time: 4 to 6 hours
When to Go: The best time to do this hike is from June through September, when the trail is free of snow. Snow can linger on trail into July. Get updates on trail conditions on the National Park Service website.
Timed Entry Permit: Park Access permit (the permit that does not include Bear Lake Road).

Chasm Lake Elevation Profile

Chasm Lake elevation profile

Please practice the seven principles of Leave No Trace: plan ahead, stay on the trail, pack out what you bring to the hiking trail, properly dispose of waste, leave areas as you found them, minimize campfire impacts, be considerate of other hikers, and do not approach or feed wildlife.


How to Hike to Chasm Lake

Step-By-Step Trail Guide

Trailhead: Longs Peak Trailhead

The hike starts at the Longs Peak Trailhead. To get here, take Highway 7 and turn onto Longs Peak Road. At the end of this road is a parking lot that can hold approximately 20 cars. Overflow parking tends to line the road as you approach the parking lot.

Hikers that are attempting to summit Longs Peak start at the same trailhead and park in the same parking lot. Due to the distance of the Longs Peak hike, most hikers arrive between 3 and 5 am to start their hike. We spoke to a park ranger who stated that the lot can be completely full by 2 am!! Car camping is not permitted in this lot.

The four of us had no desire to arrive by 2 am to get a space. So, Tim dropped me and Kara off, and just the two of us hiked to Chasm Lake. Meanwhile, Tim and Tyler hiked Twin Sisters and then picked us up after their hike.

When we arrived in the parking lot, at about 6:30 am, every space was filled and there were many cars on the roadside. We probably would have gotten away with also parking on the road but didn’t want to take the chance of getting a ticket. So, we split up.

Kara and I definitely did the better hike. Chasm Lake is amazing!!

Longs Peak Trailhead

Chasm Lake and Longs Peak trailhead

On the Trail to Chasm Lake

For the first 2 miles you will hike through a fir and pine forest. It is a steady, uphill hike the entire way. In fact, there are very few flat sections or downhill sections as you hike to Chasm Lake. This is a tough hike.

Trail through the Trees

Trail Split

Trail junctions are well marked with signs throughout the hike.

 Log Bridge to Chasm Lake


At about the 2-mile point, you emerge from the forest and begin hiking in the subalpine tundra. Once out of the trees, you get panoramic views of the mountains surrounding trail. In front of you is the massive peak of Longs Peak. Behind you are the Twin Sisters.

Out of the Trees


The stretch of trail from the edge of the forest to the trail junction for the Keyhole Route is one of the most strenuous of the hike. The trail rapidly gains elevation and you will hike up and over massive boulders and stone steps. At least the view is great, as you get closer to Longs Peak.

Hiking Trail to Longs Peak

Rocky Trail to Chasm Lake

Chasm Lake – Longs Peak Junction

3.3 miles into the hike you reach the trail junction. There are toilets here. Go left to continue on to Chasm Lake. Those hiking to Longs Peak will go right through the Boulder Field.

Chasm Lake Trail Sign

Trail Junction

This is the point where the hike really gets good. You have covered most of the elevation gain by this point and what lies in front of you are some of the best views in Rocky Mountain National Park.

In the valley to your left is Peacock Pond. The melting of Mills Glacier fills Chasm Lake, which feeds Columbine Falls and Roaring Fork, and ultimately fills Peacock Pond. The massive peaks of Longs Peak and Mt. Meeker form the backdrop of the scene.

Now, you get to enjoy a brief downhill walk and enjoy this awesome view.

How to Hike to Chasm Lake

Hike to Chasm Lake


In the late spring and early summer, you may have to hike across lingering patches of snow. It’s an easy walk along Roaring Fork before the final climb to Chasm Lake.

Roaring Fork Chasm Lake


To get up to Chasm Lake, you will have to climb up a rock fall. There will be a few spots where you will do some rock scrambling, using your hands and feet. If you are unsure where to go, follow the rock cairns. Chasm Lake lies just on the opposite side of this short but steep and tiring climb.

Final Climb before Chasm Lake

Kara on the Climb


Then, enjoy the views of Chasm Lake. Longs Peak is on the opposite side of the lake. To the right is Lady Washington and to the left is Mt. Meeker. We saw numerous rock climbers on Longs Peak the day we did this.

Chasm Lake RMNP

Kara at Chasm Lake

Tips to Have the Best Experience

Start the hike early, ideally by 7 am. During the summer months, afternoon thunderstorms are common, typically occurring by 2 pm. You need to be back in the tree line by 2 pm.

Do not expect your cell phone to work. For most of this hike we had zero cellular service. There were a few spots in clearings or at higher elevations where we got a few bars of LTE or 3G, just enough to send a text message. But don’t depend on your phone to call for help, talk to friends, or send photos to friends and family.

Be prepared to turn around early. If weather conditions change and you see approaching thunderstorms, be prepared to end your hike before you reach Chasm Lake. Your safety is more important than making it to the lake.

If you are not acclimated to the altitude, this is not a good first hike in Rocky Mountain National Park.The long distance, elevation gain, and altitude make this a tough hike. If you have not already spent time in Colorado adjusting to the altitude, I recommend that you spend a day or two acclimating to the higher elevation. Emerald Lake, Deer Mountain, and Gem Lake are good warm-up hikes.

If you plan to visit Rocky Mountain National Park from late spring through early fall, you will need a Timed Entry Permit for some areas of the park. Learn more here.

Get updates on trail conditionson the National Park Service website before you hike to Chasm Lake.

Rocky Mountain NP Travel Guide

What to Bring on the Hike

Hiking shoes. Don’t do this hike in anything other than hiking shoes or hiking boots. There’s a good chance you will hike through snow, even in the summer.

Hiking poles. Hiking poles take the stress off of your legs and help to ease leg pain and fatigue.

Water and snacks. At least 3 liters of water in the summer.

Sunscreen, hat, and sunglasses. For more than half of this hike you will be exposed to the sun, with very little shade.

Camera. Even a smartphone will do. Chasm Lake is a great place to use the panorama feature.

Rain jacket or fleece. It’s chilly at Chasm Lake. Be prepared for all weather conditions, even snow in the summer months. Pack a rain jacket and/or fleece and even another layer of clothing.

If you are new to hiking or are curious about what you should bring on a hike, check out our Hiking Gear Guide. Find out what we carry in our day packs and what we wear on the trails.

If you have any questions about hiking to Chasm Lake, let us know in the comment section below. Happy hiking!!

More Information about Rocky Mountain National Park

ROCKY MOUNTAIN NATIONAL PARK ITINERARY: How many days do you need in RMNP? Get the answer to this question and learn how to plan your itinerary in our Rocky Mountain National Park Itinerary Planner.

BEST OF ROCKY MOUNTAIN NATIONAL PARK: For a list of top experiences, read our article Best Things to do in Rocky Mountain National Park. We also have a guide to the best hikes in Rocky Mountain National Park and how to spend one day in RMNP.

MORE GREAT HIKES IN RMNP: In our Rocky Mountain National Park Hiking Guide, learn about the top hikes to do in the park. We also have detailed guides on the Continental Divide Trail to Mt. Ida, Deer Mountain, Sky Pond, Gem Lake, and Emerald and Dream Lakes.

ESTES PARK: In our Guide to Estes Park, learn about where to stay, where to eat, and what to do.

NATIONAL PARKS BY SEASON: Rocky Mountain National Park appears in our Best National Parks to visit in February, June, September, and October articles. For more information about the best times to visit the national parks, check out our Best National Parks Month-by-Month Guide.

BEST NATIONAL PARKS IN THE USA: Looking for your next big adventure? Read our article about the 15 Best National Parks, where we narrow down the long list into 15 must-see parks.

If this is part of a bigger road trip through the USA, visit our United States Travel Guide for more inspiration and travel planning tips. We also have a lot more information about Colorado in our Colorado Travel Guide.



Chasm Lake Rocky Mountain National Park


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Comments 11

  1. Avatar for Dawn

    Thank you SO much for sharing this valuable information! I am new to hiking and your article answered alot of my questions. Happy Hiking!
    Dawn Moore
    Jupiter. FLORIDA

  2. Avatar for Paul S
    Paul S

    We went on the Chasm Lake hike on Saturday. I should have read the part about the altitude. We are from Florida and have never really been hiking before. That part was tough. I’m not exactly the youngest dude on the mountain. But, it was still great. We made it to Peacock Pond which is most of the way. Some really nice views up there. Probably could have made it to Chasm Lake but it was getting late and we didn’t want to be on the mountain after dark. So, if we do it again, we’ll get out there earlier. Anyway, it was a great hike. Definitely tough for people not used to the altitude but still doable. Weather was great, although a little cold on the way down.

    1. Avatar for Julie Post
  3. Avatar for kat

    thank you so much for your posts! i couldnt plan my trip to USA without it.
    im traveling to Rocky Mountains at the end of april 28th till 1st of may. all your hikes ideas are in june.
    the only one that i saw that we can do its Deer Mountain, Bear Lake, Emerald is that the only one we will be able to do it?
    was hopping to hit some proper mountains. looks like we didnt plan our trip at the best time.

    any more ideas would be greatly appriciated.

    1. Avatar for Julie Post

      You can hike more trails in April, under two conditions. One is if the area doesn’t get a lot of springtime snow…then the trails will have less snow on them. And #2, if you have experience hiking alpine trails in the snow, and have the proper gear, you can hike in the snow. One of the issues of being there in April is that Trail Ridge Road will not yet be open, cutting you off from part of the park. You will be limited to the hikes you mentioned, basically the ones that start along Bear Lake Road and that general area. When you get to RMNP, I recommend going to the visitor center and talking to a park ranger. They will know the updated trail conditions and what is safe to hike, and point you in the right direction. Also keep an eye on the weather in April. If that area gets a large snowfall, then you will have limited trails to choose from. Cheers, Julie

  4. Avatar for Beth

    Hi Julie! We live in Colorado at 7,000 ft and hike a lot. We’re going to RMNP for two days in early October. We’re trying to decide between Sky Pond or Chasm Lake. Which one do you recommend? Thanks so much! Love your blog! Always use it to help me plan our trips!

    1. Avatar for Julie Post

      Hello Beth. Both are great hikes but Sky Pond is our favorite of the two. It’s a lot more fun to hike (the trail to Sky Pond changes more than the trail to Chasm Lake) and we think that Sky Pond is just more interesting to see. Tim and I were just talking about Sky Pond a few days ago and reminiscing about what a great experience it was. Have fun in RMNP! Cheers, Julie

  5. Avatar for sk
  6. Avatar for June
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      1. Avatar for June

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