Dirty Bismark Route - Mountain Biking

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15 miles of dirt and 1500 feet in elevation gain make this a fun ride out onto the plains.

Written by

Courtney Johnson


15.0 miles

Destination Distance From Downtown

5.1 miles


1 of 5 diamonds

Time To Complete

3 hours


All Seasons

Dog Friendly


Yes; sections on-leash

Fees Permits


Topographical Map

Trail Map

Land Website

Dirty Bismark Trail



Known as the Dirty Bismark Route, this mountain bike ride follows much of the same route as the now revamped Morgul Bismark road race with mountain and city views. Fifteen miles of dirt and 1,522 feet of elevation gain, this ride can be ridden year round weather dependent (snowmelt, rain etc.). The recommended route is to start at the Marshall Mesa Trailhead off Marshall Road. There is a parking lot and bathrooms at the trailhead.

 You will get a good warm-up taking the Marshall Valley Trail to the Cowdrey Draw. Hang a left onto Cowdrey Draw and enjoy the only singletrack descent of the entire fifteen mile ride. Cross over 66th Street and jump onto the Mayhoffer Singletree extension trail. This trail will become the Singletree Trail and connects to the Meadowlark Trail. Head south on Meadowlark till you reach the Coalton Trail- a fireroad that climbs. 

After you climb, you will hit singletrack again as you continue the ride on the High Plains Trail. High Plains will meet up with the Greenbelt Plateau Trail. Hang a right on GPT. Greenbelt has a bit of a downhill with some logs you need to clear and eventually a few rocks comprising the most technical part of the entire route. Once you hit the fence line, turn right onto Coal Steam. Once on Coal Steam you can celebrate a ride well done on this downhill back to the Marshall Mesa Trailhead.

What Makes It Great

Most of Boulder's trails are in the mountains or the foothills; the Dirty Bismark route heads east on the dirt roads on the plains. Views are spectacular, with the Flatirons and even Longs Peak visible from the open prairie land. There are no technical sections on the standard trails, though there's two or three optional spots for tricky riding along Marshall Mesa. This is a good ride for cyclists of any level, especially mixed groups. The tour itself is a wonder way to get in miles on dirt without much in the way of challenging terrain. 

Who is Going to Love It

Cyclists looking to log miles without going on pavement will love the option to tour the eastern plains. Mountain bikers who prefer easy riding in a beautiful setting will enjoy the mellow vibe of these trails. Experienced bikers looking to ride fast can have a lot of fun on these trails as well. 

Directions, Parking, & Regulations

The trailhead is on the southeast side of the road at the intersection of Highway 93 and Marshall Road, off of Marshall road (turn east off Highway 93 at the light and then a quick right).Boulder residents can park for free but non-residents must pay $5. Note that there is free parking just across Marshall Road from the entrance to Marshall Mesa. This informal gravel parking area will save you a few bucks and it’s 30 second walk to the trailhead.

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Marshall Mesa Trailhead

5258 Eldorado Springs Drive
Boulder, CO, 80302
39.955481, -105.22226

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