Dirty Bismarck

 51 votes

15.2 Miles 24.5 Kilometers



1,090' 332 m


-1,090' -332 m


5,965' 1,818 m


5,519' 1,682 m



Avg Grade (2°)


Max Grade (7°)

All Clear

5,965' 1,818 m


5,519' 1,682 m



Avg Grade (2°)


Max Grade (7°)

A fun Boulder area cruise following the famous Morgul Bismarck road course.

Building Map
Loading Map Data
Map Settings
Featured Ride


This ride follows the well-known Morgul Bismarck road cycling route - a famous race stage in the 70's and 80's.

The trails are easily accessible from Boulder, Superior, and neighboring towns, and it's mostly smooth with just a few slightly technical spots. It's just challenging enough to keep advanced riders interested, but rideable by just about everyone. This makes it a popular route, and it's often rideable almost all year.

Need To Know

There are several trailheads along this route, so start wherever it's convenient. You can also cross over Route 93 in a couple of places to ride more of the Marshall Mesa trail system.


The trail as marked here starts and ends at the Marshall Mesa trailhead, which is the largest trailhead along the trail, closest to Boulder. From the trailhead, you'll head onto the Marshall Valley Trail, which is mostly flat with a short solid-rock playground thrown in.

The trail soon crosses a bridge and meets up with Cowdrey Draw and Community Ditch trails. Take a left onto Cowdrey Draw and you'll head mostly downhill on singletrack, popping out at 66th Street.

Continue through the gate and across the road and you'll now be on the Mayhoffer-Singletree extension trail, heading towards Superior. This section twists back and forth on itself and climbs just a bit. It's a serene, rural part of the ride - you're likely to see horses or cows along the way, and it feels like you're farther away from the neighboring roads than you are.

Next you'll meet up with the Meadowlark Trail, which climbs a bit, right next to an office building. The rural feel will go away for a bit until you head away from the office building and back towards a reservoir. Then the trail heads south next to McCaslin Blvd. until you reach the Coalton Trailhead.

This section of trail (Coalton Trail) l is mostly dirt road, and it gets you to the top of Marshall Mesa. Keep going until you reach yet another small trailhead to meet up with the High Plains trail.

Follow the High Plains trail, which is singletrack with a few mildly technical rocky sections. You'll eventually reach the Greenbelt Plateau trailhead where you can either cross Route 93 to meet up with the rest of the Marshall Mesa trails, or continue along this ride back towards the start.

Continuing along this ride, you'll end up on the High Plains Trail, which is singletrack, with a few mildly technical rocky sections. From here, turn right onto Greenbelt Plateau Trail and climb this mellow, mostly smooth section of trail. After the trail starts back downhill, take a right turn over a couple of log stairs, then down a bit more to some more log stairs and a short technical rocky bit, and over a bridge to cross the irrigation ditch.

Turn left onto the Community Ditch trail heading west, and ride until you reach Route 93. Here, you have another option to cross 93 and ride the Marshall Mesa trails to the west. But to get back to the trailhead, take a right onto Coal Seam.

Coal Seam is mostly downhill back to the trailhead, and somewhat technical, with twists and turns and rocks to keep things interesting. Ride the final rock garden, or ride around it, and you'll be back where you started.

History & Background

The Morgul Bismarck is a relatively famous stage from the Red Zinger / Coors Classic road cycling race from the 1970's and 1980's. Over time, trails along the perimeter of this classic road route have been built, making the Dirty Bismarck MTB trail.


Rate Featured Ride


3.1 from 51 votes

Get On-Trail Navigation

Send to Phone
Your Check-Ins


Sep 24, 2016
Ben Hagener
Fun start and finish with a lot of road in between. Stay away on windy days!
Sep 21, 2016
John Roccaforte
Sep 21, 2016
Don Blake
Trail in great shape
Sep 5, 2016
Sep 4, 2016
Lori Li
Sep 4, 2016
Krystyna Zatorski
Started from Coalton Trailhead. 15.0 miles in 2:25 Accidentally turned right on 66th street instead of crossing the street onto Singletree. 15mi — 2h 25m
Aug 15, 2016
Stephanie Warner
Aug 7, 2016
Michael Ratzloff
Used 4L water by mile 13. 15.2mi — 2h 18m

Stewarded By

Trail Ratings

  3.1 from 51 votes


  3.1 from 51 votes
1 Star
2 Star
3 Star
4 Star
5 Star


in Colorado


568 Views Last Month
7,410 Since Mar 21, 2013
Easy Easy



All Clear on Aug 7, 2016


MTB Project is part of the REI Co-op family,
where a life outdoors is a life well lived.

Shop REI Mountain Bike

MTB Project is supported by

Support Your Local IMBA Chapter