Colorado, Colorado Hikes, Rocky Mountain National Park, US National Parks

Rocky Mountain National Park Hikes: Chasm Lake

I’m sure my opinion will change as we explore more of Rocky but, so far, Chasm Lake is my absolute favorite hike in the park! I’ve done this hike twice; first with a friend in late August two summers back, and second with my mom at the end of last June.

Chasm Lake shares a trailhead with Longs Peak, one of the more popular Colorado 14ers. A hike up Longs requires an extremely early morning start (we’re talking 1:00am) so parking is a nightmare. I’d absolutely recommend against attempting this hike on a weekend unless you feel like waking up ridiculously early.

For the first hike, we arrived at the trailhead at 7:00am on a Friday and already found ourselves parking along the road because the lot was full. The second time around, we arrived at 6:45am on a Thursday and had no trouble finding parking; I’m sure all the lingering snow acted as somewhat of a deterrent.

The trail to Chasm Lake begins with a steady climb through a pine forest. Be prepared for a lot (and I mean a lot) of stairs. After about 2 miles (3.2 km), the trail emerges from the trees and into the alpine zone that you’ll be in for the remainder of the hike. The undeniable upside to hiking in alpine environments is the beauty. The downside is the wind. It’s usually chilly and gusty, but by no means did that detract from our enjoyment of this hike.

Looking toward Chasm Lake and Longs Peak from just above tree line
Looking back toward the plains
Approaching Chasm Lake in June
Approaching Chasm Lake in August

At around the 3.5 mile (5.6 km) mark, the Longs Peak trail splits off to the right. For Chasm Lake, stay left. Beyond the split, the trail curves around a hillside and then cuts horizontally across a steep slope above Peacock Pool and Columbine Falls.

Columbine Falls and Peacock Pool
Mom navigates the snow field

This section of the hike can be downright dangerous in inclement weather; I’d recommend avoiding it during rain and wearing microspikes if there’s any snow or ice. Much of this section was snow-covered during our late June hike, and most people who didn’t have microspikes were unable to make it across the snowfield.

Past the snowfield, the terrain flattens and the trail leads into a marshy area. There is a bathroom here, and the RMNP hiking book I own has dubbed it the most scenic privy in Colorado. I must say, I agree. Where else can you enjoy this view while sitting on the toilet?


The final challenge of this hike is a sizable headwall. The trail sign at the base simply points up, so up we went. The trail is actually more obvious and mildly less vertical than it appears from this vantage point, but we did get in a good laugh at the sign. This section was also covered in snow in June, and the intense rays of the sun resulted in soft snow that often gave way beneath our feet. I slipped a couple times, even with my microspikes.

Once you’ve cleared the headwall, you’ll find yourself at the rocky shore of Chasm Lake. Longs Peak rises in the background; the large, smooth somewhat geometric section of the mountain is called The Diamond. I’ve never been a good judge of vertical height, but I was shocked to learn that the elevation difference between the lake and the summit of Longs is almost 2500 feet (760 m)! It certainly makes you feel very small.

Chasm Lake in June
Chasm Lake in August

I think the photos do a pretty good job of explaining why this hike has been added to my All Time Favorite Hikes list… and why I will absolutely be repeating this hike many more times in the future.

The Important Stuff:

  • Getting there: Chasm Lake is reached from the Longs Peak Trailhead at the end of Longs Peak Road off CO Highway 7
  • Fees and passes: despite the fact that you don’t cross through an entrance station to reach the trailhead, the $25/car daily or $35/car weekly park entrance fee (or interagency pass) still applies. From May-Oct, if you arrive after 9:00am you will also need a timed entry permit to access this trailhead
  • Hiking: 8.4 miles (13.6 km) round-trip with 2360 feet (720 m) of elevation gain; moderate-strenuous thanks to the elevation
  • Camping: there is a first-come-first-serve campground near the trailhead, but it’s small and fills quickly; be aware that sleeping in your car at the trailhead is prohibited since it’s a national park
  • Other: the second half of this hike is entirely above treeline; there is no shade or shelter and you’re completely exposed to the elements, so come prepared for all types of weather and be ready to turn back at any signs of thunderstorms

18 thoughts on “Rocky Mountain National Park Hikes: Chasm Lake”

  1. Love the complete difference in the lakes between the two different months you visited. Just added this hike to my All Trails list for whenever we make it out to Colorado!

    Liked by 1 person

  2. I can see why it’s your favourite. I like your June and August comparisons. I’d be tempted to drag my skates up there (that frozen lake looks so beautiful…though probably need to do this a few months earlier!)

    Liked by 1 person

    1. Yeah, the lake was beginning to thaw when we were there and I saw a photo from someone else 4 days later and the ice was gone! I was shocked how quickly it melted.

      It would be a gorgeous winter destination I’m sure, but that one section where we had to navigate the snow field is really dicey in the winter. Lots of avalanche risk. I’d be a little nervous.


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