Boulder is one of the world’s top cycling towns, but local mountain bikers have long faced an ironic dilemma: To reach quality trails, they had to load their bikes on a car. Most single-track trails in city and county open space have been closed to cyclists since 1983, when open-space managers decided bikes were having an ill effect on the trails and hikers. But recently bike trails began resurfacing on planners’ drawing boards, thanks to a winning combination of activism and trail-building volunteerism by the Boulder Mountainbike Alliance. Since 2007, more than 20 miles of single-track have been opened to bikes—and created a collection of superb new rides.

Hikers, runners, and horseback riders share these trails with bikers, so when land managers were looking to design new trails they hired experts from Boulder-based International Mountain Bicycling Association to craft routes with tight turns and rocky obstacles, in order to keep bike speeds reasonable. “Trail design is key to shared use,” says IMBA communications director Mark Eller.

The Boulder Mountainbike Alliance hopes to work with open-space planners on a long wish list of additional trails in the near future—including a bikeable link from Eldorado Canyon to Walker Ranch in the foothills, more trails inside the Betasso Preserve (above Four Mile Canyon), and a trail from Boulder to Heil Valley Ranch near Lyons. This summer, construction will ramp up on the Valmont Bike Park, with 45 acres of technical single-track, slopestyle courses, and cyclocross obstacles in northeast Boulder.

Until then, enjoy these three excellent new rides.

Flatirons Vista-Spring Brook Loops
The Dirty Bismarck
Picture Rock Trail

Flatirons Vista-Spring Brook Loops
Distance 8.8 miles
Skill Level Beginner to Intermediate
Trailhead Highway 93, 0.3 miles south of junction with Highway 128

This short figure-eight loop is a good intro to single-track, with modest climbs and technical difficulties—and you can easily cut it short if the ride is proving too much for the kids. Follow the brand-new Prairie Vista Trail up a beautiful draw, topping out in ponderosa pine forest. Continue west and then back north along a mesa’s edge, with sweeping views across the southern Flatirons. Hang a sharp left onto the Doudy Draw Trail, and then descend a couple of hundred feet with one long switchback.

After crossing a creek, head west again on the newly completed Spring Brook Loop. Go clockwise, starting with a moderate, somewhat rocky climb, followed by tight turns through the pines as you head back north. The narrow trail emerges on a grassy point with stunning views of Eldorado and Shadow canyons, and then swoops back down to the Doudy Draw Trail. Climb to the mesa and follow the double-track Flatirons Vista North Trail to the trailhead.

Bonus Miles From the upper trail junction on the Spring Brook Loop, climb a short switchback to a gravel road and follow this downhill 0.3 miles to find amazing rippled walls of Dakota sandstone above the road, the remnants of an ancient ocean beach. Return the way you came to resume the loop.

The Dirty Bismarck
Distance 15 miles
Skill Level Beginner
Trailhead Marshall Mesa, southeast corner of Highway 93 and Highway 157

The Morgul Bismarck was a famous 13-mile circuit stage of the Red Zinger and Coors Classic bike races in the ’70s and ’80s. (Greg LeMond and Davis Phinney raced it, among others.) Now, just as traffic and commercial development in Superior have tainted the road loop’s allure, a mountain-biking alternative is close to being completed. Cyclists can ride all but about three miles of the 15-mile “Dirty Bismarck” on single-track trails and dirt roads; the final off-pavement links are slated to be completed this year.

Follow the single-track Marshall Draw Trail east, across short patches of slickrock, to the Cowdrey Draw Trail, which contours hillsides to 66th Street. Follow the paved road to the right until it turns to dirt after a third of a mile and reaches West Coal Creek Drive; take this dirt road northeast until you’re nearly to Superior, then wind around the south end of town on the dirt Singletree Trail. The east end of this trail dead-ends before you reach McCaslin Boulevard, but a quick jog to the right on a dirt road will get you up to the main road. Follow McCaslin south over the sharp hill they called “The Hump” in the Morgul-Bismarck days to reach a traffic light and the Coalton Trail parking on the right. (New trails soon will bypass the dirt and paved roads between Cowdrey Draw Trail and Coalton Trail.) Climb the double-track Coalton Trail west, and then veer south past a vantage point with great views of the Flatirons, the Indian Peaks, and Longs Peak. Connect with the brand-new High Plains Trail, which glides mostly downhill for nearly 2.5 miles. From the Greenbelt Plateau trailhead, follow double-track back north, over a small hill, to reach the Community Ditch. Head left until you’ve nearly reached Highway 93, and then descend the fun Coal Seam Trail to the car.

It’s harder to describe this loop than it is to ride it—the mostly smooth paths and modest climbs make this a great outing for fit beginners.

Bonus Miles At the Greenbelt Plateau trailhead, cross Highway 93 and follow the Flatirons Vista North and Doudy Draw trails down to Community Ditch. Return along the irrigation ditch to the Coal Seam Trail and the car, adding five scenic miles to the loop.

Picture Rock Trail
15 miles
Skill Level Intermediate
Trailhead Red Gulch Road in Lyons, off Old St. Vrain Road. Park in public lots in Lyons (five minutes away by bike) if the trailhead lot is full.

This killer new trail on the north side of Heil Valley Ranch climbs about 1,000 feet above the southern outskirts of Lyons. The 5.5-mile climb was built for mountain biking, with long switchbacks, banked hairpin turns, and sandstone ramps over big rocks and roots—and there are plenty of technical obstacles to keep things interesting. The route begins in grassy meadows and winds through stands of ponderosa and juniper, and over twisting creek beds. Midway through the climb, you’ll pass a large silo and stone foundation, and then ride over the slickrock floor of an old quarry. The ride is increasingly rocky and challenging toward the top—intermediate riders may find they put a foot down now and then.

When the Picture Rock Trail ends, follow the Wild Turkey Trail to the left for a loop with superb views of Mt. Meeker and Longs Peak, returning along the St. Vrain canyon rim. Rejoin the Picture Rock Trail and enjoy a well-earned ride down the mountain—just watch out for hikers and uphill riders as you roll through blind curves.

Bonus Miles Park at the south end of Heil Valley Ranch (take Lefthand Canyon Road to Geer Canyon Road), and climb the rocky 2.5-mile Wapiti Trail, and then descend along the Wild Turkey and Picture Rock trails. Follow paved Old St. Vrain Road west to Hall Ranch, and ride the nine-mile lollipop loop there. Return the way you came for a total of nearly 40 miles of technical climbing and descents—a solid day for any rider.

Dougald MacDonald is a contributing editor for 5280. E-mail him at