A dirt loop that roughly parallels the course of the old Morgul Bismark road race.
Since it's a loop you can start/finish at any of the THs, and you may run in either direction. The total route is 15.2 miles and is a good mix of single track trail and some more smooth trail surfaces. It's not overly technical and has about 1000ft of elevation gain with two challenging climbs. The route is completely exposed and is known for challenging winds; especially on the Coalton Trail & High Plains Trail. The full Dirty Bismarck route includes the Marshall Valley Trail, Cowdrey Draw Trail, Mayhoffer Trail, Singletree Trail, Meadowlark Trail, Coalton Trail, High Plains Trail, Greenbelt Plateau Trail, and Coal Seam Trail. The routes name comes from a famous road bicycle race called the Morgul-Bismarck hosted throughout the 80's on roads similar to this route. When a full loop trail version of the route was completed the new trail route name became known as the "Dirty Bismarck".
Below is a detailed description of the route. The route is continuous and very easy to follow but sections have been given many different official trail names.
Start at the Marshall Mesa Trailhead Gate. This is the clockwise route description.
Head east on the Marshall Valley Trail for 1 mile. You come to the intersection with the Community Ditch Trail, but stay straight to head east on the Cowdrey Draw Trail for another 1 mile. You cross 66th St. and the trail becomes the Mayhoffer/Singletree Trail. After 2.5 miles the trail turns into the Meadowlark Trail and in 3 more miles you eventually come to the Coalton Trailhead. The trail turns right on to the Coalton Trail. After 3 miles the trail becomes the High Plains Trail. After about 2.6 miles you'll make a right on the Greenbelt Plateau Trail. In 1.2 miles you encounter the only real tricky turn; make sure to make a left onto the Community Ditch Trail and only proceed for 0.3 mile until just before Highway 93. Before Highway 93 make a sharp right turn on to the Coal Seam Trail. You will be on the Coal Seam Trail for 0.6 mile before coming to the finish gate at the Marshal Mesa Trailhead where you started.