Skyline Traverse

Adventurers: Michael, Tracy & Erik
The Skyline Traverse is an unofficial running route in Boulder, Colorado that covers all five “peaks” or summits in the Flat Iron’s trail system (South Boulder, Bear, Green, Flagstaff and Sanitas). Linking them together has become more popular, however there is not a lot of literature on the best way to do it.

Category: Trail Running

Start: Boulder, Colorado
Trail head: There are a few places you can start, especially considering there is no “official order” in which to run the peaks. We recommend starting at the Mount Sanitas Trailhead (the peak you will actually run last). Begin your run through the neighborhoods that lead to Chautauqua and traverse 
across Bluebell Road to the Mesa Trail that will lead you to Shadow Canyon where you will start your first big ascent.
Trails: As noted above, start by running the from the Mount Sanitas Trail head to Chautauqua and taking Bluebell Road to Mesa Trail to Shadow Canyon. Shadow Canyon is 1.1 miles long and packs in 1800 vertical feet. Once you ascend this steep, rocky climb you will emerge at a trail that connects South Boulder Peak and Bear Peak. Start by heading left and tackling South Boulder first. After summiting, run back down the way you came and then head the opposite direction from where you originally emerged to head to the summit of Bear Peak. The distance between these two peaks is only .5 miles and it’s relatively easy to bang out. It’s important to start with South Boulder and then do Bear so that you can exit off of Bear Peak via the Bear Peak West Ridge that will take you to towards Green Mountain. This decent is initially very rocky and you may need to use your hands to stabilize yourself at times.
After a nice long decent from Bear you will approach a juncture where you can go right or left. The Green Bear Trail on the left leads towards Green Mountain. You will know this is the right trail because it begins to ascend rather than descend and the trail markers are clear as well. The Green Mountain ascent is very runnable. Only once you get up near the summit does it because very rocky and requires hiking. Make sure you take a right on Green Mountain West Ridge to head up to the top. After you’ve summited run back down the same way you came up, not off the other side, so that you can exit the mountain onto Flagstaff Road via Green Mountain West Ridge.
Once you reach Flagstaff road, run down the pavement a short ways (about .5 miles) until you reach a trail map on the right hand side that allows you to take Long Canyon Trail. Descent Long Canyon Trail for 1.1 miles and you will exit the trail at what we would consider to be a confusing trailhead on the left hand side of the road with a sign pointing to the Flagstaff Summit. This part is VERY confusing because the sign points you the complete wrong direction. To get to the Flagstaff summit take the Ute Trail and keep going until you reach a pavilion, near the pavilion you sill see a sign that says “Flagstaff Summit.” The summit itself is very underwhelming and consists of a couple of big rocks at a look out point, there is no climbing required.
From the Flagstaff Summit, cross the road to take Flagstaff Trail. This trail crosses the paved road 5 different times. Keep on the trail, being mindful of the fast moving traffic. You will soon see signs for the Halfway House, continue in that direction. You will be looking out for the Panorama Point which you will pass and move onto Viewpoint Trail. This will take you down into town right by the Boulder Creek via the Boulder Creek Trail. From here cross the road by way of the foot bridge and take the Red Rocks Spur Trail (look for the Settlers Peak Trailhead) which will take you up and over a hill and allow you to descend down to the Mount Sanitas Trailhead.
If you’ve parked at the Mount Sanitas Trailhead you have the option to power up and finish up the traverse or stop by the car if you are in need of additional food or water.
The final peak, Mount Sanitas, is about 2.6 miles round trip and has plenty of false summits. Keep going until you reach the very last set of boulders! Once you’ve summited, all you have to do is cruise back down to the car.
Distance: 22.6 miles
Vertical Gain: 7,090 feet

Duration: 7 hours
Weather: Sunny and 75 degrees
Risk: Dehydration in hot weather, technical terrain
Tips: Start early! It gets very hot, quickly. Pack plenty of food and water. Parking near the Sanitas Trail head allows you to knock out the road running first, rather than run it after you’ve bagged all of the peaks (if you park on the other side of the traverse, near South Boulder or Bear). No body wants to finish with a long flat run…
Mesa Trail
Bear Peak
running bear peak