Four Pass Loop Hike: Aspen Snowmass Wilderness, Colorado

Posted on August 21, 2022

Four Pass Loop Hike: Aspen Snowmass Wilderness, Colorado

What is the Four Pass Loop Hike and why did we do it?

The Four Pass Loop hike is a 28-mile loop within the Aspen Snowmass Wilderness that summits four saddleback passes between peaks. This wilderness space is home to the famous Maroon Bells, which is one of our favorite places in the world! This trail is infamous among hikers for being challenging and potentially dangerous all while providing some of the best untouched wilderness views in the States.

We were lucky that we did not do this alone! Three of our dear friends joined us and we could not have done it without them. Our friend Brent lives in Colorado and is always down for trying something new and brings the BEST attitude. There were moments where we would not have made it without his optimism. Our other two friends, Erika and Ryan, traveled from Michigan to tackle this. It all started with wanting to do a backpacking trip and after some wine we said “why don’t we just do it?”. They are the adventurous type, have their own blog – Gerbers Underway – and they will be doing big things soon! What we as a group did not realize was that this was not like other hikes, but a different beast unto itself.

On a personal note, I (Leeann) have a life goal of thru-hiking the Pacific Crest Trail. I have been obsessed with any PCT information and content for years now. I don’t know when this will happen as this task takes about 5-6 months to complete – but I will do it! Though I did read the book “Wild”, that is not what started me off down this 2650 mile rabbit hole! This video from Elina Osborne started me off and I have been dreaming of it ever since. This hiking loop is a way to practice the combination of backpacking, high altitude, and having a deeper motivation for wanting to live in the woods.

Logistics of Beginning the Four Pass Loop Hike

There are two ways to get on to the Four Pass Loop – via Aspen or Crested Butte. Far and away the Aspen side is busier than the Crested Butte entrance as the Crested Butte entrance includes an extra two miles each way! We entered via the Aspen route specifically at the Maroon Bells site.

Because parking is impossible at the Maroon Bells visitors area overnight and between the hours of 8:00am – 5:00pm, no one is allowed to drive there and must take a shuttle bus – we opted for the shuttle bus. The shuttle tickets are available mid-April and I secured our 5 tickets for a specific time of day (11:30am) on a specific day (June 16th) on April 12th and cost $20 each. Our bus time slot was busy and we entered on a weekday, I would recommend getting the tickets as soon as you can.

Since we live outside of Boulder, Colorado, we had a 3.5 hour drive to get to Aspen Highlands ski area where the shuttle picks up. We opted to park as Aspen Highlands as it was the most accessible for overnighters. Because we had that drive, the risk of saving money on parking and relying on a different bus to get us to the shuttle was not worth it. That being said, parking for 3 days ended up costing us $120.. woof.

We decided to complete the loop counterclockwise. This decision was based on the topography map and comments about the snow melt levels as well as water crossings.

Mountain Pass One: Buckskin Pass (12,500 feet)

The hike from Maroon Lake to Crater Lake was straight forward as we had completed it many times before. But this time was different as we quickly discovered the difference between hiking with a daypack and a full backpack with 3 days of food and gear. The altitude was more of an issue than we realized – even for those who live at 5500 feet normally. The hike starts around 9,000 feet and going counter clockwise around the loop will take you up to 12,500 feet quickly. This was the most elevation gain of any of the passes, which is why we wanted to get it over with first with fresh legs!

From Crater Lake to the top of Buckskin pass was a beautiful windy trail through the trees and along a river. We eventually had to cross the river which was more fun than we anticipated! Roo was able to cross the river all on her own! This river was decently strong, but that may have been partially due to the time in the season we went. It may be more of a stream/creek during drier times in the season after the majority of the snowmelt.

Once we got above the treeline is when the major switchbacks started. There was some snow on parts of the switchbacks, but nothing that required microspikes. Once we were reaching the top of the pass, there was a snow cornice that hung over about six feet. We decided to go off of the official trail and rockclimb to the right of the trail rather than tackle that snow cornice. The last mile leading up to the pass took us over an hour and had us questioning our decision to do the trail. The altitude, the gear weight, the heat, and our nerves around the snow were all things contributing to the feeling that we may quit. (After we complete the loop, Ryan told us he almost called the trip at this point and I don’t blame him!)

Once we got to the top, we understood why people do this. The clear views of the mountaintops above the treeline for miles and miles was worth the struggle. Because there was no snow at the top of the pass so we had a snack and celebrated!

The Sadlers at the top of Buckskin pass on the Four Pass Loop Hike

Camping Night One

We camped for the night about one – two miles before Snowmass Lake near a beautiful low area next to a meandering river. The first night of camping, we already figured out some kinks in gear. The Gerbers tent poles elastic had degraded and our tent was honestly too small for two adults and a dog. Brent had prepared perfectly and everything was fine for him!

In the morning, packing up camp took much longer than we expected and we finally got to hiking around 7:30am. We walked the short distance to Snowmass Lake and had breakfast. Snowmass Lake is one of the most beautiful spots along the trail so I would definitely recommend spending some time there.

Mountain Pass Two: Trail Rider Pass (12,420 feet)

Getting to Trail Rider Pass proved more difficult than we realized. We were warned by another hiker that there was a sketchy snow section that we should avoid. Rather than hiking at a 45 degree angle snow shelf with a drop on the other side, we opted to rock climb up and over. Though this was the better choice, the 0.2 miles of rock climbing and jumping took us nearly two hours to complete. Poor Max had to navigate the section with Roo who was scared of the rocks.

After the rock climbing and hopping, there were snow fields that required us to use the snow steps created by other hikers. By this time, the snow was warming and post holing was inevitable. The snow fields turned out to be okay and the remainder of this pass was clear. When we got to the top, we had planned to stop and snack – but the group was greeted by thunderheads on the other of the pass. It was just 12:00pm noon and passes are known for thunderstorms after noon, which we were prepared for. We didn’t realize they were going to be so punctual and show up directly at noon.

The next two hours were chaotic as we had to run down 1500 feet of elevation to get to the treeline as the thunderstorm ramped up. By the time we got to the trees, it was hailing and lightening all around. Both our nerves and knees were deeply impacted.

We had a lot of miles to cover after the rock climbing and storm set us behind by nearly three hours. The group walked through some beautiful meadows but were unable to fully appreciate them.

The Sadlers on top of Trail Rider Pass looking down at Snowmass Lake

The group excited at the top of Trail Rider Pass thankful we made it over the rock fields

Camping Night Two

We ended up camping earlier than we had hoped for, but all of us had nothing left in the tank. After an early dinner and climbing into our tents by 6:00pm we had hoped for a relaxing evening. Around 8:00pm, it started raining quite heavily and consistently. This area is not known for few persistent downpours, but rather tiny spurts of rain . It rained all night long but had stopped around 4:00am. We left camp by 5:15am as we had two more passes and 10 miles to tackle.

Mountain Pass Three: Frigid Air Pass (12,415 feet)

The hike up Frigid Air Pass was the most pleasant and easiest hiking we had encountered. The only barrier is that the meadows we would have typically been able to fly over, were completely waterlogged and required us to step on either side of the stream..I mean trail.

There were some other snowfields but truly everything else went to plan. Do not be fooled by a false summit! We learned from our past mistakes and summited by 8:00am which ensured less chance of thunderstorms.

The Sadlers on top of Frigid Air Pass – muddy and happy.

Three of Four Passes complete on the Four Pass Loop!

Mountain Pass Four: West Maroon Pass (12,500 feet)

The trail between Frigid Air Pass and West Maroon Pass was relatively flat with little elevation loss/gain (around 1000 feet) between the two. The hike up West Maroon was the steepest of all the passes, but it was relatively straight forward. At the top of the pass, it was the smallest space we had seen thus far and unfortunately the busiest. Because a good amount of people do the loop clockwise and it was Saturday – a lots of hikers were just starting.

The hike down is where is started to get scary. The snow was warming based on the time of day and the amount of people that had just come up the pass from that side. The group had a few slipping moments that could have been life ending, let alone hike ending. Panic attacks ensued and it was a rough time.. the rest of the time. There was a steep snow field that we had to climb down, but did not have the proper gear (an ice axe) in case we slipped. It was a slow and terrifying descent into the flattish meadow. Members of the group are still struggling with some of the impacts of the intensity of this experience.

Getting Back to Crater Lake + Aspen Highlands Shuttle

Unfortunately we thought that that was our hardest part of the day, but we were met with more barriers. We cruised for several miles before coming to a water crossing. Other groups had alerted us that this was a tough crossing without the rain from the prior night. After eight hours of down pouring rain had turned this from difficult to impossible.

We could not find an easier crossing so we decided to bushwhack on the side we were on because the trail crossed the river twice. It was only 0.8 miles but ended up taking nearly three hours of bushwhacking and rock climbing. This experience was a continuation of the anxiety that we were feeling along with just wanting to be done. There were several rock fields that we had to traverse and rock walls to climb. It was hard to determine what – between the river or the rock climbs – was the better choice.

We eventually made it to one of the last shuttles that would take us back to Aspen Highlands area. On this shuttle ride, Roo slept while we cried, laughed, and took a deep breath.

Max and Leeann at the top of West Maroon Pass

What would we change and do differently?

We should have waited until mid-July or August before we completed the Four Pass Loop Hike. The amount of snow and water in mid-June was too much and we were not prepared for early summer rainstorms.
Listened to the rangers as they warned us that only one group had completed it thus far in the season. Blind confidence can lead to poor decisions.
Acclimated a bit more. We should have spent the night at around 9000 feet as that would have helped with the recalibration for both Denver folks as well as helped the Michigan friends.
I was still getting over being sick (the illness) and had a tough time with breathing. I wish that I had been fully healthy and had done extra cardiovascular exercises in preparation.

One thing we were happy about was us having our Garmin InReach that had emergency messaging, location tracking, and the SOS button. Luckily we did not need these items, but knowing that help and safety was only a button away was calming.

Overall Thoughts on the Four Pass Loop Hike

Overall, the group is proud of ourselves for completing the loop. We could not have done it without every single person as we all brought different strengths and shined at different moments. Most of our gear also worked so I’m proud of the research and preparation that we did prior to getting out into the wilderness. This made us think critically the hikes/backpacking trips we consider in the future. That is all part of learning our capabilities and boundaries in the wilderness.

This experience just made me more excited that confident that I can eventually tackle the Pacific Crest Trail.