Sourdough Trail


Photo of Sourdough Trailhead sign and trail

The first section of trail #835 runs north from the Sourdough Trailhead and climbs gently, sometimes on old roads. It gains 1,000' in this first three miles past Fourmile Creek and is fairly level for the next two miles. It climbs a couple switchbacks to the trail's highest point along the 10,200' contour.

The Sourdough Trail dips down, passing the Little Raven Trail and on to the Red Rock Trailhead. From the Brainard Lake Road, the trail continues to drop elevation by about 500' in two miles. It crosses South Saint Vrain Creek on a wide bridge, and intersects with the South Saint Vrain Trail #909 on the other side. The Sourdough Trail drops to cross National Forest System Road 113, and continues on to Beaver Reservoir. The trail continues on the other side of the Beaver Reservoir Road. It then joins with Buchanan Pass Trail near Camp Dick Campground.

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At a Glance

Permit Info: No permits are required at this time.
Usage: Light-Medium
Restrictions: Motorized vehicles prohibited. Fishing and hunting are allowed in accordance with regulations established by the Colorado Parks & Wildlife.
Closest Towns: Nederland and Ward, Colorado
Water: Occasional streams; treat water for drinking.
Restroom: Vault toilets at Sourdough Trailhead and near Middle St. Vrain Trailhead at Camp Dick
Operated By: U.S. Forest Service
Information Center: Boulder Ranger District, 2140 Yarmouth Ave, Boulder, CO 80301, Phone 303-541-2500, Fax 303-541-2515; Contact Us

General Information

Directions: From Nederland, travel seven miles north on Colorado Highway 72. Turn west onto National Forest System Road 298, signed as the turnoff for the University of Colorado Mountain Research Station. A parking area is not far on the left. Three other trailheads serve Sourdough Trail: Red Rock Trailhead, Beaver Reservoir Trailhead, and Middle Saint Vrain Trailhead.

Recreation Map

Map showing recreational areas. Map Information



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Mountain Biking

The Sourdough Trail runs nearly 15 miles long across ridges and drainages west of Colorado Highway 72. Ride it end to end with a vehicle shuttle or take it a segment at a time. This trail connects to the Little Raven, Waldrop and South Saint Vrain trails in the Brainard Lake Recreation Area and to the Buchanan Pass Trail at its north end for endless segment and loop opportunities. Access Sourdough Trail from Sourdough, Red Rock, Beaver Reservoir and Middle Saint Vrain Trailheads.

Difficulty Level: Easy to Difficult


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Horse Riding & Camping

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Areas & Activities

Campgrounds At-A-Glance


  Area/Length : 
Sourdough Trailhead to: Red Rock Trailhead - 5.8 miles; Beaver Creek Trailhead – 12.6 miles; Buchana

  Latitude : 

  Longitude : 

  Elevation : 
9,200' - 10,200'