Hike Boulder's Skyline Traverse

Colorado Mount Sanitas Trailhead

Added by Ian Glass

Like suffer-fest hikes? Boulder's Skyline Traverse connects the city's five tallest peaks into one hell of a hike.

Have you ever reached the bottom of a hike with some friends and thought, 'That was nice, but I'd still like to hike more... a lot more.'? Then the Skyline Traverse is for you. Instead of hiking just Green Mountain or Bear Peak, the Skyline Traverse links South Boulder Peak, Bear Peak, Green Mountain, Flagstaff Mountain, and Mount Sanitas into one long day. After finishing this 'pleasant stroll' you won't want to think about hiking for at least a few days.

Because you will be hiking all day (8-10 hours) from one end of Boulder to the other, it is recommended that you use a car-shuttle. You will need to have one car at the Mount Sanitas trailhead parking lot and the other at Shanahan Ridge Trailhead (parking at NCAR works too, Shanahan TH is just closer to South Boulder Peak). From here, it's choose your own adventure. You can either hike from Mount Sanitas to South Boulder Peak or visa versa. I would recommend starting at SB Peak for two reasons: 1) You knock off the two toughest peaks early in the day. 2) When you drive back to Shanahan TH to get the second car, you can stop at the Southern Sun for an adventure celebration. Right? Do it.

So starting off from the Shanahan TH (at around 5:30-6am), follow the North Fork Shanahan trail for about 1 mile until you reach the Mesa trail. Take a left (south) on the Mesa trail and hike for another mile until you reach a fork in the path for Shadow Canyon North trail. Take a right onto the Shadow Canyon North trail. The trail will eventually become Shadow Canyon trail, which you will take all the way to the top. The trail will spit you out on saddle between SB Peak and Bear Beak. Turn left on the trail to tag the summit of SB Peak. After a quick celebration dance, double-back and traverse over to Bear Peak.

From the summit of Bear Peak, you want to head down the Bear Peak West Ridge trail (Crucial! Don't hike down Fern Canyon). You'll follow the BP West Ridge trail down into (what I think is) one of the prettiest parts of Boulder. There is an isolate aspen groove with an gentle stream running through it. Great place to string up a hammock... but not today. You still got three peaks to go. BP West Ridge trail reaches a fork and you'll want to hang a left onto Green Bear trail. You will take the Green Bear trail 1.5 miles to the Green Mountain West Ridge Trail, which you'll turn right on and head up to the Green Mountain summit.

Once you've summited Green Mountain, double-back on the trail you took up until you reach the Ranger trail (0.3 miles from the summit). Follow the Ranger trail down for roughly a mile until it forks towards Flagstaff road... which is an actual road (if you've started down Gregory Canyon, you've gone too far). You will need to cross Flagstaff road in order to reach Flagstaff summit. This is where things get a little wanky. There really isn't a clearly denoted 'summit' on Flagstaff AND there is no real trail to take you there. It's just kinda flat with trees everywhere. Just find the highest rock you can and move on. Flagstaff just isn't worth it. I might sound bitter but after you do it, you'll see where I'm coming from.

So, from Flagstaff's non-existent summit find your way to the Flagstaff trail. I don't really have a beta on this except for, just keep hiking North on Flagstaff until you find an established trail. Follow Flagstaff trail down to Panorama/View Point trail which is a large overlook of the city with a parking lot. Skirt the overlook to your left and BAM! you are on View Point trail. This trail will lead you into a neighborhood. Keep walking straight and you will cross over into Eben G. Fine park. Follow the Boulder Creek path (it's paved) left a couple hundred yards and you will reach a bridge that leads you under an overpass. Go through the underpass to the park on the other side of Canyon Rd. You will find the Red Rocks trail. Follow the Red Rocks trail for half a mile and you will reach your first car at the Sanitas parking lot... but you're not done yet.

Cross the parking lot and take the Mount Sanitas trail to the summit. From the summit you can double-back on the trail you hiked up or take the really mellow Sanitas Valley trail back to your car.

Hooray! You did it! Now got celebrate at the Souther Sun!

*Note: This hike can be done all year long but one should be encouraged to use micro-spikes during the winter season.

**Also: Not many photos because I was mid-suffer.

Pack List

  • Two cars (so you can shuttle... or one car and good friend willing to pick you up)
  • Daypack
  • Water bottle (at least 2 liters)
  • Snacks on snacks
  • Lunch
  • Layers
  • Rain jacket
  • Sunglasses
  • Sun hat
  • Micro-spikes (if there is ice)
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Fitness, Hiking, Running

Skill Level:



Year Round

Trail Type:



16.4 Miles

Elev. Gain:

6300 Feet



Easy Parking

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How to Get There

Incredible views on a full-day hike.

This hike was so fun for my friend an I. I believe it took us around 13 hours (she was really slow :-| ) but damn it was still so good. The views to the west from Green Mountain, Bear Peak, and S. Boulder Peak were amazing. The Flatirons are literally like the door to an unbelievable landscape behind them. Take plenty of water and snacks and possibly trekking poles.

26 days ago

about 1 month ago

Google maps link

I plan on giving this hike a try early October. I messed around with google maps might not be the perfect route but I think it is pretty close to the explanation that was left on the blog post. Thanks for the direction -Casey https://drive.google.com/open?id=1S5wl2sfCceos0p4Gqv9gR5zuMC8&usp=sharing

about 1 month ago

5 months ago

Heading out for this soon!

Great review! A must-do for Colorado dwellers who love trail running and long hikes. I'll be giving it a shot in a week or so!

5 months ago

10 months ago

Incredible views and a very challenging run, best way to knock out all the peaks at once! Be careful on some of the peaks with scree though as even rocks that appear stable can slide.

10 months ago

Added by Ian Glass

Videographer/Photographer based in Boulder, CO with a penchant for the outdoors // @ianvaso

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