by Elise Ott, 2020 Four Pass Loop thru-hiker
The Four Pass Loop is a difficult, 28-mile loop trail located in the Maroon Bells-Snowmass Wilderness area in Central Colorado. The trail traverses four mountain passes over 12,000 feet and can be hiked in 3-5 days.
Region: Mountain West (Maroon Bells-Snowmass Wilderness, Central Colorado)
Distance: 28 miles (3-4 days)
Physical Difficulty: Difficult
- 7,752 feet of cumulative elevation gain
- Several sections of 1,000+ feet of elevation gain / mile
- Much of the hike is above treeline, leading to greater exposure
- High average elevation
Logistical Difficulty: Difficult
- High elevation, narrow weather window
- Must plan to be over mountain passes by early afternoon to avoid thunderstorms
- The Forest Service began requiring permits for backcountry camping on Feb. 15, 2023.
- Accessing trailheads requires advance reservations for shuttle or parking or, alternatively, a 4WD vehicle
Season: Summer, Early Fall
Elevation (Average): ~11,000 feet
Starting Elevation: 9,580 feet
Max Elevation: 12,500 feet
Total Elevation Gain: 7,752 feet
Hiking the Four Pass Loop
This hike is basically nonstop views with a healthy amount of physical challenge. If you’re the type of backpacker who likes to be rewarded for your climbs with epic 360 mountain vistas, this is definitely the trip for you.
You can camp at some of the most beautiful backcountry sites I’ve ever seen. Catching both sunset and sunrise at Snowmass Lake is the kind of thing bucket lists are made of—not to mention falling asleep to the sound of King Falls’ rushing water in Fravert Basin.
That being said, these beautiful backcountry places aren’t reached without some backcountry effort. The climbs, especially up Trail Rider Pass (going clockwise), are enough to make your legs shake at sea level; add 12,000 feet of elevation into the equation and even fairly fit people will feel it’s a challenge. If you’re coming from sea level, a few days of acclimatization will make your trip much more enjoyable.
Most say it’s easier to do this loop clockwise, and that’s what I did. The trail itself is straightforward and well-marked so as long as you can follow a map, navigation shouldn’t be a challenge.
For backpackers who don’t mind needing a bit of logistical foresight—carrying a bear can or intense climbs—Four Pass Loop is a true treat with some of the best backcountry Colorado has to offer.
How to get to the Four Pass Loop
Nearest City: Aspen, Colorado (10.8 miles) or Crested Butte, Colorado (14 miles)
Maroon Lake Trailhead (when starting from Aspen)
West Maroon Trailhead (when starting from Crested Butte)
While Four Pass Loop is obviously a loop and you will start and end at the same place, there are two trailheads to choose from and each presents its own logistical challenges. Pick your poison.
The more popular option, and the one I found easiest, is entering from Maroon Lake Trailhead, located about 10 miles outside of Aspen, Colorado. Due to the popularity of the trailhead (you’ve probably seen the lake on a few Colorado postcards), reservations are required to reach it whether you are driving yourself or taking a shuttle. Reservations and a lot of detailed information can be found at the Aspen Chamber website here.
There are three options to consider when entering from Maroon Lake Trailhead:
1) Reserve a $10 round-trip shuttle in advance from Aspen Highlands Ski Area to the trailhead. The shuttle leaves every 15 minutes from 8 a.m. to 3 p.m.. If you’re late it will leave without you and they will not let you on the next one. So be on time, or better yet, be early. I was able to get reservations about two weeks in advance for Fourth of July weekend, but they definitely fill up so it benefits you to plan ahead. You can park your car in the garage at Aspen Highlands, but it is $30 and can fill up (note: the garage says $30 maximum, and when I parked there that is all I was charged for 3 days; however, this could vary). Another option is to park at Ruby Park in downtown Aspen and take the free RFTA shuttle to Aspen Highlands (where you will catch the shuttle).
2) Have an awesome friend drop you off at the trailhead between 6 a.m. and 8 a.m. (the road is closed to private vehicles outside this window), and make sure you still get a $10 one-way ticket for the shuttle back to Aspen Highlands (and presumably if you don’t live there, a way to get back home after).
3) Reserve a $10/vehicle 2-night overnight parking permit that is good from 6 a.m. on your start date to 6 p.m. two days later (for 60 hours total). This allows you to park at the trailhead; however, you must arrive before 8 a.m. or after 5 p.m. because the road is closed to private vehicles during the day.
Phew, I told you this trail had logistical challenges. If dealing with shuttles and parking reservations isn’t your bag and you have a high clearance, preferably 4WD vehicle, you can begin the trail from West Maroon Trailhead on the Crested Butte side. You’ll follow Gothic Road (CO 317) out of Crested Butte for 13 miles. It’s a dirt road and should be passable in most vehicles until you reach Gothic (about 7.9 miles in). After that, you will likely need a high clearance/4WD vehicle. Once you get to the trailhead, it’s about 3.1 miles of hiking to the junction where you will meet up with the Four Pass Loop (which you can take in either direction).
When to Hike the Four Pass Loop
The best season to hike Four Pass Loop is summer, but you can successfully hike the trail in early fall with good weather. Because it is a high-altitude hike, it is covered in snow well into June and it’s very possible to encounter snow in July depending on the snowpack from the previous winter. For the best wild flowers, aim for August. If you can get good weather in early fall during the changing of the aspen leaves, it’s beautiful.
This hike is moderately trafficked, so hiking during the week will mean fewer crowds.
Another important factor to consider is thunderstorms. It is very common to encounter hail and lightning above treeline during the summer in the early afternoon–my personal rule for safety is to be back below treeline before noon (although it can storm earlier). Keeping an eye on the weather may also help you decide which direction to take the loop. Because the trail does not go back below treeline between West Maroon and Frigid Air Pass, you may want to knock out those two passes first if the weather looks nice, or last if not. My first day on the loop had a clear forecast so even though we started around 10 a.m., we decided to go for the first two passes that afternoon. Here’s my itinerary to show what a trip could look like (It’s important to note that I hiked the Four Pass Loop before overnight backcountry permits were required.):
Day 1: West Maroon Pass (12,490 feet) + Frigid Air Pass (12,405 feet)
I hiked about 14 miles from West Maroon Trailhead to our first campsite.
Day 2: Trail Rider Pass (12,415 feet)
I hiked about 8 miles from camp over Trail Rider Pass, the steepest ascent of the trip. I highly recommend taking a short day and camping at Snowmass Lake.
Day 3: Buckskin Pass (12,462 feet)
On the final day I started early, made it up and over the pass before afternoon rain, and made it back to the trailhead with plenty of time to catch a shuttle back to the car.
Four Pass Loop Terrain
Four Pass Loop is a well-maintained, easy to follow trail. It’s mostly dirt with some rocky sections. It can become looser and rockier toward the top of the passes, but there is no route-finding involved (as long as the trail isn’t covered in snow).
There are several stream crossings throughout the loop, so you should check with the Forest Service to see what the current trail conditions are like before you go. While I definitely got wet, the stream crossings were very moderate in July 2020 (a dry year for Colorado).
During my trip, I did run into a couple of sections with dense avalanche debris. This can happen early in the season after an avalanche-prone winter—so just be ready to go a little slower and get creative navigating around trees.
Four Pass Loop Logistics
Camping and Permits: Four Pass Loop is located in the Maroon Bells-Snowmass Wilderness within White River National Forest. Starting Feb. 15, 2023, all overnight visitors must obtain a permit in advance. Permits and camping information can be obtained here.
Water: There are ample water sources throughout the hike (several of which you will have to cross). The earlier in the season you go, the more water you will see due to snowmelt. The climbs are fairly exposed, so be sure to carry enough water to last you the climb.
Special Gear: Bear canisters or any IGBC approved bear-resistant container are required to hike Four Pass Loop. You will be ticketed and asked to leave if you don’t have one and in my experience I did encounter several rangers on the hike.
In the early season or after a high snow year, it may help to have microspikes for snow patches on the high mountain passes.
Know Before You Go
The most important things to remember before hiking Four Pass Loop are checking what kind of snow levels you are dealing with and having your trailhead logistics sorted. Getting shuttles and parking requires some advanced planning.
Also, don’t forget to bring a bear can—a fed bear is a dead bear. The Forest Service also iterates it’s very important to have a plan for your human waste (aka your poop). They highly recommend considering WAG bags. WAG stands for Waste Alleviation and Gelling. A WAG bag is a disposable, sealable bag with some odor-destroying chemicals plus a chemical that turns your waste into a stable gel. All of which is to say, it’s better than pooping into a Ziploc bag. If you don’t use a WAG bag, please be sure to bury it 6 to 8 inches deep at least 200 feet from water, camp, and trails.
Resources
Booking Shuttle or Parking Reservations
Getting a Permit and Camping Information
