Dirty Bismarck

 57 votes
Building Map
Loading Map Data
Map Settings
Featured Ride

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°)

Minor Issues

6 days agoUpdate

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

Mike Ahnemann


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 57 votes

Get On-Trail Navigation

Send to Phone
Your Check-Ins


Dec 28, 2016
Trevor Steffensen
Nov 16, 2016
Tyson Shelley
One of the windiest Ride I've ever been on! 15.2mi — 2h 19m
Nov 13, 2016
Caleb Joyce
Clockwise is definitely the way to ride this
Oct 29, 2016
Deji Fatunla
Oct 23, 2016
JW Show
Oct 21, 2016
mike erickson
one section closed
Oct 16, 2016
Craig Gomulka
Oct 15, 2016
Galen Horton
This was a great trail, even with a lot of traffic, lot of rocks, & a LOT of climbing - I would advise riding this counterclockwise. Bucket List! 25.2mi

Stewarded By

Trail Ratings

  3.1 from 57 votes


  3.1 from 57 votes
1 Star
2 Star
3 Star
4 Star
5 Star


in Colorado


241 Views Last Month
8,841 Since Mar 21, 2013
Easy Easy



Minor Issues 6 days ago
Muddy - Lots of mud on the southern singletrack but only for about 200 yards, the rest is clear.
Update ConditionsHistory

Getting forecast...

This ride is more like 20 to 30% singletrack. Sep 1, 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