How to Hike Aspen, Colorado’s Four Pass Loop

Backpacking the Four Pass Loop in the Maroon Bells Wilderness near Aspen, Colorado

Wow. Just wow. I’ve had my eye on the Four Pass Loop near Aspen since I moved to Colorado. It’s frequently on “best of” hiking trails lists for the state, and I’ve even seen mention of it being one of the best hiking trails in the world. With all this hype and all the hiking I’ve done, you might think I’d end up disappointed. Not so! I was, in fact, totally blown away by this 28-mile(ish) trail. It was nothing short of amazing, despite a near-hypothermia experience!

What, exactly, made this trek so special? So many things!

First of all, I was greeted by a beautiful bull moose with an epic mountain backdrop as soon as I arrived. Second, I can’t even tell you how spectacular the views were! Snowmass Lake, my goodness! Third, although we missed peak wildflower season, there were still plenty of gold, purple, and pink late-summer flowers dotting the landscape, and the first hints of fall were beginning to peak out. Fourth, this hike had the perfect amount of elevation gain (7,870 feet of elevation gain in total according to AllTrails) to be a challenge and to feel like an accomplishment, but not enough that it felt overly strenuous. And finally, I completed the loop with a truly fantastic group of people. There was so much camaraderie and positivity in the group, and it felt like we were all truly watching out for one another.

I cannot recommend this backpacking trip enough!

Getting there

A bull moose hangs out in Maroon Lake – the entrance to the Maroon Bells Wilderness.

The Maroon Bells Wilderness, where the Four Pass Loop is located, is possibly the most beautiful place I’ve ever been. And it’s not a well-kept secret. Tourists, hikers, backpackers, and bikers flock to the area, and because of this, there are strict protocols in place to limit the amount of visitors and their impact to the area.

In order to visit, at least from the Aspen side, you have two options. Option number one is to make a reservation to park in the wilderness. This will cost you $10 unless you have an annual parks pass, in which case it is free, and you have to do this far in advance as passes sell out quickly. They generally go on sale the first of the month for the next month. For example, if you’re looking to get a permit to park there in August, you will need to get online to get your permit on July 1.

Option number two, which requires less advance planning, is to ride a shuttle from the Aspen Highlands ski area. You do need to purchase a timed, dated pass in advance through the Aspen Chamber, which will cost you $15.95 for a round-trip ride, but these sell out less quickly. We bought tickets for our group of five about two weeks in advance and there were plenty of slots left. The shuttle runs from Aspen Highlands to Maroon Bells every 15 minutes from 8 am to 5 pm in the summer. You can park at Aspen Highlands to catch the shuttle, but it costs $30 per day to park there. A cheaper alternative is to park at the Buttermilk Lot, which is $6 per day, and take the free local city bus up to the Highlands. Note: you will have to transfer buses once. We hopped on at Buttermilk, hopped off at Maroon Creek Rd., and caught another bus up to Aspen Highlands. It was quite easy, and we simply confirmed with the bus drivers that we were going in the correct direction. Because you must check in for your Maroon Bells shuttle 45 minutes in advance, give yourself some extra time to make it up to Aspen Highlands.

Bonus of taking the shuttle: there are some real characters out in Aspen! Meet them and enjoy their company. We had a particularly colorful shuttle driver on the way up to the wilderness who pointed out lots interesting sites along the way, such as penned horses, llamas, and emus, a pond with a blue heron, and wished us well in seeing the various moose that wander near the entrance to the wilderness.

On the way back, you do not reserve the shuttle for a specific day or time. You simply line up when you get back to the entrance, as there are clear signs letting you know where the bus will pick up, and you wait for a seat.

Once You’ve Arrived

Backpacking past Crater Lake into the Maroon Bells Wilderness. Photo by Rachel Davis.

Upon your arrival, follow the path past Maroon Lake (where we saw the bull moose!) to the Maroon Snowmass Trail #1975. Here, you can snap a photo of the trail map if you have not downloaded it in advance (which of course I always recommend but don’t always do!). Follow the trail out the Crater Lake, which is another lake with a fantastic mountain backdrop, and here, you can decide to follow the loop clockwise or counterclockwise, depending on the order in which you’d like to hike over the passes. This is really up to your preference, but we went clockwise and I’d really recommend doing this for a couple of reasons.

In my opinion, the most beautiful part of the trek was the hike down from Trail Rider Pass to Snowmass Lake. Had we gone the other way, we would have hiked away from the lake rather than toward it. Additionally, I thought the easiest pass to hike over was Buckskin, which was our last. Though it was a long climb, there were a bunch of switchbacks and the grade remained super reasonable the entire time. Alternatively, the hike down from Buckskin was fairly steep, so if you were going the opposite way, you’d get a challenge right off the bat.

There are a ton of dispersed camping sites throughout the loop, so you should not have a problem finding a camping spot. However, there is some competition to get the best spots (and those closest to water), so if you’re picky, you may wish to get up and at ‘em early. There is water availability for a large part of the loop as well, but probably the longest stretch without water is from maybe a mile before West Maroon Pass (if you’re going clockwise) to a mile or two past Frigid Air Pass, so be sure to plan in advance for this section.

We completed the loop in three days, but you can of course break it up however you so choose. We hiked about 12 miles our first day, climbing up over West Maroon and Frigid Air passes, then about eight miles the second day, climbing over Trail Rider pass, then about eight miles the third day as well, getting up and over Buckskin pass and back to the trailhead.

Things to Consider

Hiking down from Trail Rider Pass to Snowmass Lake. Photo by Rachel Davis.

As an avid outdoorswoman and very experienced hiker, I hate to admit this, but I found myself less prepared than I should have been during this trek, and it almost put me in a pretty dangerous situation. Bear canisters are required here, as there have been some problems with human-bear interactions. (Ursacks are allowed as well. Though I could not find this information online, there is a sign in the Maroon Bells wilderness confirming this). If you’ve ever carried a bear canister, you know that they’re heavy, bulky, and take up half your pack.

Because of this, I skimped on bringing some of the layers I normally would have, such as a pair of pants to hike in, rain pants, etc. I had warm clothes for camp, but I try to keep these dry and clean solely for camp, as I’m a cold sleeper and more likely to freeze when I’m sedentary than when I’m actively hiking and producing heat.

And guess what? Mother Nature showed me fiercely that skimping on layers and general preparedness in the name of weight in a dangerous idea. This is a high elevation trail. It begins at 9,580 feet and reaches 12,500 feet at its highest altitude. We got caught in some heavy, consistent rain our second day on the trail. We were all in shorts and raincoats, but were soaked to the bone anyway. As we began to climb up to Trail Rider Pass, the air temperature began to drop incredibly quickly, and as we looked up toward the pass, we watched in amazement as snow began to fall. In August. I was all right for a while, but began to get colder and colder as we climbed higher. I stopped to wait for the rest of the group at about the tree line, and just that minute or so of waiting made me feel like I was playing a really dangerous game. I was suddenly freezing, soaking wet, and about to march straight up into a snowstorm with no extra layers, no cell service, and no other way to get out of the mountains. As the rest of the group caught up, we all saw that another woman in the group, Cat, was shivering and upset. We made the decision then and there to set up a couple of the tents, get into dry clothes, and huddle together to bring our body temperatures up before continuing up into the snow. I shivered and held onto Cat for at least a half hour before beginning to feel better.

After about an hour, the rain stopped and we came out of our tents. I refused to take my camp clothes off; I was just too cold to get back into my wet gear. As we emerged, we cheered as we realized there was a patch of blue across the sky. We packed up, beginning our ascent once again, and low and behold the blue sky followed us up the pass. As we got to the top, we were rewarded with a perfectly clear sky and possibly the most beautiful view of the mountains I’d ever seen. Then, after only another mile and a half, we got to stop and hang out at a clear, turquoise alpine lake, where we warmed our bodies and souls with a sunshine and bourbon.

We got lucky. Really lucky. This situation could have been much worse had we not stopped to think for a minute about the smart way to proceed, and had we not gotten lucky with the afternoon weather. This was an incredibly valuable lesson that I obviously needed to learn again. Conditions in the mountains can change incredibly quickly, and it can snow any time of year. If you’re going to recreate there, you need to keep the risks in mind and be prepared for anything, no matter how inconvenient it may be. I will not be going back out there without more layers (and likely some Hot Hands), that is for certain.

Learn from my mistakes, friends. Be prepared and respect the mountains, because they are always in charge.

As always, if you enjoyed this blog post, be sure to follow me on Instagram, subscribe to my YouTube channel, and join my e-mail list! In the comments, I’d love to hear if you’ve ever had any close calls in the mountains!

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Published by Audrey

Hi! My name is Audrey, otherwise known as Glowstick on trail. I've always been into hiking, adventuring, and the outdoors, but these things took a backseat as I worked on my career in public relations for several years in Washington, D.C. In 2018, I decided that I was discontent with city life. Instead of working on my career, I needed to work on my happiness. So, I reprioritized. I quit my (amazing) job at World Wildlife Fund, thru-hiked the Appalachian Trail, and relocated to beautiful Boulder, Colorado, where I work in climate communications and climb mountains every chance that I get.

7 thoughts on “How to Hike Aspen, Colorado’s Four Pass Loop

    1. You totally should! The Aspen wilderness was seriously one of the most beautiful places I’ve ever been. And if you ever need tips on what to do and where to go in Boulder, let me know!

      Liked by 1 person

  1. Sounds like an incredible hike! I’m so glad I went into reading this knowing that everything turned out ok, because I was on the edge of my seat there for a little bit!

    Liked by 1 person

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