Get Fat

James Dziezynski | Boulder Weekly

A boulder mountain bike trail round-upBoulder County’s mountain biking has enjoyed a steady evolution in the past five years. Led by the relentless efforts of the Boulder Mountainbike Alliance (BMA), the network of trails available to fat-tire enthusiasts has grown and expanded the variety of riding in our backyard. Whether you are in the mood for fast singletrack, lung-searing climbs, technical playgrounds or all-day epics, there are plenty of options in and around Boulder to get your fix. Here’s a rundown of some of the most popular and accessible trails in the area (note that trail mileage is round-trip).

Marshall Mesa/Dowdy Draw/Flatirons Vista

8-10 miles

How to get there:

Both the Marshall Mesa and Flatirons Vista trailheads are off Highway 93 south of Boulder. Marshall Mesa is on the east side of the road at the intersection of Highway 93 and Marshall Road/CO 170 (turn east onto Marshall Road then immediately to the right for the trailhead). Flatirons Vista is farther south on Highway 93, a few hundred yards past the intersection of Highway 93 and Highway 128, on the west side of the road.

Difficulty: Beginner to intermediate

Terrain: Well-maintained single- and double-track trails with a few dirt roads. Mostly non-technical with a few short climbs. Incredible views.

Summary: The last few years have been good for south Boulder mountain bikers, thanks to the web of interconnected trails between Marshall Mesa and Eldorado Springs. The nontechnical trails and gorgeous rolling scenery appeal to all levels of bikers, but are especially good for beginners and intermediates. Wildflowers, shady forests, a few speedy singletrack sections and majestic views of the Flatirons await. Best of all, the southern exposure means these trails are often rideable yearround.

Heil Valley Ranch

9 miles

How to get there:

Go north on U.S. 36 about six miles from Broadway/U.S. 36 and turn west onto Left Hand Canyon (at the Greenbriar Inn).
Proceed approximately one mile, and the signed turn off for Heil Valley
Ranch will be on your right. Follow a dirt road a little more than a
mile to the terminus parking lot.

Difficulty: Intermediate

Terrain: Alternating rocky and smooth singletrack with sustained, moderate climbs and two loop options.

Summary: No one
Boulder trail system has changed so much in the past few years as Heil.
Originally a rocky, semitechnical, lollipop loop with a screaming
downhill, Heil has morphed into a more intermediate-friendly trail in
the past few years. The 2.5-mile Wapiti trail has been slowed down and
smoothed out and serves as a gateway for two loops at the top. The older
2.6-mile Ponderosa Loop is a jarring, rocky ride that never picks up
much speed and is punishing for hardtails. In contrast, the newer
2.9-mile Wild Turkey Trail loop has good flow, is less rocky (though
still fairly bouncy) and offers different challenges, depending on which
way the loop is ridden. Wild Turkey also feeds into the Picture Rock
Trail (see below).

Hall Ranch

9-11 miles

How to get there:

For the
Bitterbrush (technical terrain) trailhead, follow U.S. 36 to Lyons, then
west on Highway 7 one mile. The turn off is on the right (north) side
of the road, with ample parking. For the Antelope Trailhead, take U.S.
36 to Highway 7 but go east (right). Less than a mile up, turn left onto
Apple Valley Road, then another few miles to Antelope Road (left at the
fork) to a small parking lot.

Difficulty: Intermediate to advanced

Terrain: The best of everything: challenging, technical rock garden, sustained climbing and super-fast and fun singletrack lollipop loop.

Summary: Get
ready to get your flow on! Hall Ranch’s two entrances connect into the
smooth, super speedy and downright gorgeous Bitterbrush/Nelson trail
combo, arguably the best in Boulder

If technical riding is your thing, start at the 3.7-mile Bitterbrush
trail entrance. A one-mile warm up (with a few good low-grade technical
sections) leads to the infamous rock garden, a grueling mile of
wonderful technical obstacles that are tough but rideable for skilled
bikers. The opportunity for sessions and finding new, creative lines is
nearly endless! Intermediate and advanced beginners can hit up the
Antelope Trail, a onemile alternate trail that eschews technicality for a
good (at times, steep) climb.

trails merge into the last mile-plus of the Bitterbrush, a sweet,
steady, mostly non-technical climb that ends at the 2.2mile Nelson Loop.
Get ready to blast off on the speedy Nelson Loop and go supersonic on
the return of the Bitterbrush Trail.

Picture Rock

5.2 miles

How to get there:

Ride from Heil Ranch via
the Wild Turkey Trail, or park in Lyons by taking U.S. 36 to Highway 7
west, then left onto Old St. Vrain Road 0.3 miles, left onto Red Gulch
Road and 0.2 miles to parking on the west (right) side of the road.

Difficulty: Intermediate with long, sustained climbs

Terrain: Rocky switchbacks dominate the upper trails, while fast, smooth and edgy singletrack makes up the lower sections.

Summary: Picture
Rock was the great unifier, providing a singletrack option to connect
Heil Valley Ranch and Hall Ranch. As a descent, it quickly becomes
apparent that the upper trail is made for climbing. Rocky switchbacks
never let you build up much steam, and the hard, embedded, triangular
rocks can get tedious. The bottom two miles are faster, non-technical
and open up through old farms and grassy fields. The long and gradual
ascent was more what Picture Rock was designed for, though the same
cobbles and stone pizzas in the trail force you to stay focused for the
last three miles up to Heil.

Walker Ranch

7.6 miles

How to get there:

From Chautauqua, follow
Flagstaff Road eight miles west. Just past Myers Ranch, look for the
road to Walker Ranch Homestead and trailhead. The dirt road is straight
ahead at a bend in the road.

Difficulty: Intermediate to advanced

Terrain: A
climber’s delight with tough ascents either way you ride the loop. A mix
of fast singletrack and loose hills with a smattering of technical
obstacles and a hike-a-bike staircase section.

Summary: The 7.6-mile loop of Walker is essentially two trails, depending on which way you start.

gives you a mile of fast and loose downhill followed by steep climbing
with the occasional technical push. A reward of flowy-fast singletrack
awaits before descending a steep staircase and ending the ride with a
punishing climb out on loose dirt roads and steep, relentless
switchbacks (though climbercentric bikers will love it!).
Clockwise gives you a tough, brief, steep start followed by a fun
descent on the aforementioned switchbacks. Climb the stairs for a
forested, steady ascent to an all-too-short but fun downhill. End the
clockwise ride with a sustained but not overly steep mile-long climb to
the parking lot.

Betasso Preserve

3.2 miles

How to get there:

Head up Boulder Canyon
west four miles out of town and turn right onto steep Sugarloaf Road. Go
approximately two miles to Betasso Road on your right and then less
than a mile to the trailhead on the north (left) side.

Difficulty: Beginner to intermediate

Terrain: Fast, clean singletrack that can be edgy at times. Good climbs balanced with good flow.

Summary: Betasso
is made for speed — which is why it’s a suitable trail for beginners
learning the basics of riding and experts who want to hammer out
sub-20-minute loops. The direction of this loop changes monthly and both
ways offer speedy descents and good climbs that are great endurance
builders. Never a truly technical trail, opening up and riding full
speed puts you on the edge of control with a reward of nirvana-like flow
or agony-of-defeat type crashes. A wonderful place for newer riders to
learn how to step up their game. An optional connector trail goes
directly to Boulder Canyon and is slightly more technical (and more
steep) than the Betasso Loop.

Honorable Mention

Rabbit Mountain in
Lyons is a trail with five miles of options and good scenery. While it
doesn’t excel in any one type of riding, it’s a quality destination for
riders of all abilities. Wonderland Lake/ Sage Trail in north
Boulder is essentially a web of dirt roads that go under Highway U.S. 36
and open up into the area around the Boulder Reservoir. And next year,
the Valmont Bike Park will offer dirt jumps of all sizes, freeride terrain and more.

Not far from town:

Getting bored? Try these options, all roughly within an hour of Boulder. White Ranch in Golden has big climbs and a big network of trails that can link into nearby Apex, Golden Gate State Park, Matthew Winters and more. Centennial Cone up Clear Creek Canyon is 16-plus miles of big climbs and edge-of-your-seat, non-technical singletrack. West Magnolia Trails and Sourdough Trail are west of Boulder and have some sweet riding for those ready to explore. Finally, up north, Devil’s Backbone & Blue Sky Trail in Loveland/Fort Collins offer a whole new intermediate network of beautiful trails — just watch out for snakes!

Resources For
more info and maps, go to Boulder Mountainbike Alliance (www. or Boulder County Open Space