Why we love it: Panoramic views of the Front Range, but very close to Boulder.
When to go: Anytime—there isn’t a bad time of the year to tackle this trek.
In 1859, Marshall Mesa—5.5 miles south of downtown Boulder—was the site of Colorado Territory’s first coal discovery. The town of Marshall was a rough-and-tumble mining town bigger than Boulder, replete with shacks, company stores, and saloons galore. Today, it is one of the best close-to-Boulder rec areas.
Historic photographs and rock displays at the trailhead orient visitors to the mesa’s evolution from ancient beach to muggy coal swamp to coal-mining boomtown. I recommend two loops—for hikers, a beautiful 2.5-mile-long stroll and for mountain bikers, a 15-mile-long route. Either way, at the first junction I usually head east along the Marshall Valley Trail. Where this trail crosses a canal, the hiking loop turns right onto the pedestrian-only Marshall Mesa Trail. Bikers should continue straight to join the Cowdrey Draw Trail.
The hiking loop heads southwest for 0.7 mile until it joins the Community Ditch Trail. Head west here for another half mile, where a short, right-hand spur leads to the Coal Seam Trail, which returns you to the trailhead.
The biking loop follows the Cowdrey Draw Trail 0.8 mile to a paved road. Cross it, then hop on the Mayhoffer-Singletree Trail, followed by the Meadowlark Trail, which ends at the McCaslin-Coalton parking lot. From here a steep pull west up the Coalton Trail brings you to the mesa top. A further 2.6 miles on the flat, winding singletrack of the High Plains Trail lands you on the Greenbelt Plateau Trail, which heads north to the Community Ditch Trail. Here, a short spur to the west joins the Coal Seam Trail for the last half mile back to your car.
Both loops offer fantastic views of the mountains as well as the area’s largest remaining parcel of intact grasslands, home to prairie dogs, ferrets, and prairie chickens. Should you see wispy, gray smoke seeping out of the ground, don’t be alarmed—underground coal fires have been burning here continuously for nearly 150 years.
Getting there: From Denver, take I-25 North to U.S. 36 West and exit at 217A/McCaslin Boulevard. Turn left onto McCaslin, then right onto CO-170/Marshall Road. After four miles turn left at the T. Marshall Mesa Open Space is on the left after another quarter mile.