ElevationAscent: 1,750' 534 m
Descent: -1,750' -534 m
High: 6,679' 2,036 m
Low: 5,464' 1,665 m
GradeAvg Grade: 6% (3°)
Max Grade: 23% (13°)
Popular rides nearby
Jamestown Slaughterhouse Loop
11.2 mi 17.9 km • Loop • 2,138 ft Ascent 651.55 m Ascent
Chapman Drive Out-And-Back
11.4 mi 18.4 km • Out and Back • 1,343 ft Ascent 409.29 m Ascent
Ceran St. Vrain to Miller Rock
6.2 mi 9.9 km • Loop • 897 ft Ascent 273.36 m Ascent
Valmont Bike Park - Singletrack Hotlap
2.0 mi 3.2 km • Loop • 78 ft Ascent 23.73 m Ascent
Coney Buchanan Loop
11.6 mi 18.6 km • Loop • 1,467 ft Ascent 447.04 m Ascent
A Short Homestead Tour
8.1 mi 13.0 km • Loop • 981 ft Ascent 298.88 m Ascent
“A favorite for Boulder area riders - scenery, singletrack, technical sections... it's got it all!”— Michael Ahnemann
Electric Mountain Bikes Unknown
This trail is one of the most popular trails within 40 minutes of Longmont/Boulder, which means it can get very crowded, especially on weekends. There can also be significant horseback traffic, so be prepared for frequent stops along the descent as you yield to uphill riders, horses, and hikers. It can be frustrating because the descents are so much fun - but be courteous... it's a challenging trail for horses, and they can be easily spooked.
Need to Know
- Easiest: Start from the Antelope trailhead and link Antelope Trail, Bitterbrush - Upper Section & Nelson Loop.
- More difficult/longer: Park in town or at Bitterbrush TH and ride the road to Antelope Trail. Link Bitterbrush - Upper Section & Nelson Loop before descending Bitterbrush - Lower Section (rock garden) to your car.
You can also ride a short section of road to link up with Picture Rock trail and Heil Ranch for a big day in the saddle.
Or you might choose to relax after your ride by hanging out in the park by the creek in Lyons and taking a dip to cool off, or by tossing back a pint or two at the popular Oskar Blues brewery in town.
Starting on Bitterbrush - Lower Section, the singletrack begins right at the end of the upper parking lot. There's a nice sign there to help you get your bearings. Climbing starts almost immediately, but the trail starts off mostly smooth. Before long, you'll start riding up and over some small rocks, and the trail will get rockier as you climb.
About 3/4 of a mile in, the well-known rock garden starts. From here, it's a steep climb with frequent big technical moves over rock formations. You won't need to be a trials rider to clean this section, but you'll need to be a skilled mountain biker with enough fitness to keep your heart from jumping out of your chest.
There's a bench at the top of this section with a nice view - a perfect spot for a quick snack if you need it. Otherwise, continue down a short descent and merge onto the singletrack (Bitterbrush - Upper Section) coming up from the Antelope Trail. Settle in for a mostly grandual and smooth climb for about a mile and a half up to the Nelson Loop.
The Nelson Loop can be ridden either direction, although clockwise seems to be the most common. You'll climb further to the highpoint at about 6700' where there's a hiker's only trail heading back down to the trailhead and another bench to rest on. Here you'll be rewarded with 360 degree views. Notably, you'll see Mt. Meeker and Longs Peak. The rest of the loop from this point is a fantastic descent.
Now it's downhill almost the entire way back down to where you merged onto the Antelope Trail. You can either merge back onto Bitterbrush - Lower Section and re-trace your steps, or add a quick out and back by continuing on the Antelope Trail down to its start and riding back up to the Bitterbrush junction. Antelope is a mostly smooth, intermediate trail - it's a fun detour if you've got the energy.
Once you start heading back down Bitterbrush - Lower Section, you'll bounce your way back down through the Rock Garden, and it's almost all downhill from here back to your car.
History & Background
More than 20 different families lived and operated businesses in the area that we now call Hall Ranch. Some prospected, some farmed, and some quarried sandstone. In the mid-1940s, Hallyn and June Hall began ranching on what became known as the Hall Ranch. For more than 50 years, this property was a working foothills ranch. The Hall family expanded their land ownership and grazed livestock throughout the property. They also operated other businesses including logging and rock quarrying.
Local Club: Boulder Mountainbike Alliance
May 20, 2020: Help kids save dirt jumps in Longmont
Land Manager: Boulder County, CO - Parks and Open Space