Arapaho-Roosevelt National Forest
Sourdough Trail #835

Sourdough Trailhead to (one way):

• Red Rocks Trailhead: 5.8 miles
• Buchanan Pass Trailhead: 14.7 miles
Red Rock Trailhead to:

• Beaver Bog Trailhead: 5.8 miles
Beaver Bog Trailhead to:

• Beaver Creek Trailhead: 1 miles
Beaver Creek Trailhead to:

• Buchanan Pass Trailhead: 2 miles
Elevations:

• Sourdough Trailhead: 9,200'
• High point of Niwot Ridge: 10,200'
• Red Rock Trailhead: 10,080'
• Beaver Bog Trailhead: 9,200'
• Beaver Creek Trailhead: 9,160'
• Buchanan Pass Trailhead: 8,500'

This trail sees moderate use from May through November (open year round) and is rated as Easiest to More Difficult.

USGS Maps: Ward and Allenspark Quads

Trailhead Location: There are five trailhead locations for accessing the Sourdough Trail: Sourdough Trailhead (southern terminus); Red Rock Trailhead; Beaver Bog Trailhead; Beaver Creek Trailhead; and Buchanan Pass Trailhead (northern terminus). All of these are off of Highway 72, the Peak-to-Peak Highway.

For Sourdough Trailhead: About seven miles north of Nederland on Highway 72, turn west onto gravel NFSR (National Forest System Road) 298, signed as the turnoff for the University of Colorado Mountain Research Station. About half a mile from the highway, the Sourdough Trailhead parking area is on the left, and the trail to the right.

For Red Rock Trailhead: About 12 miles north of Nederland on Highway 72, just north of the town of Ward, follow signs for the Brainard Lake Recreation Area (County Road 102, National Forest System Road (NFSR) 112). Red Rock Trailhead is two miles up this paved road, just before the entrance fee station for Brainard Lake (at the winter closure gate).

For Beaver Bog and Beaver Creek Trailheads: About 15 miles north of Nederland and seven miles south of the intersection of Highway 7 and 72 on CO 72, turn west onto gravel County Road 96 towards Beaver Reservoir and the Tahosa Boy Scout Camp. Go about 1.5 miles and take a left at the fork in the road and go to the Beaver Bog Trailhead or take the right at the fork and go to Beaver Creek Trailhead; go about one more mile, either way.

For Buchanan Pass Trailhead: About four miles south of the intersection of Highways 7 and 72, at mile marker 50, turn west on paved NFSR 114 (follow signs for camping). Go one mile to Camp Dick and park in the trailhead parking lot at the west end of the campground.

Sourdough Trail #835 travels 14.7 miles along the east side of the mountains over forested terrain across several creek drainages. It gains 1,000 feet in the first three miles past Fourmile Creek, then is fairly level for another two miles before dropping down 500 feet to the South St. Vrain Creek in two miles, passing the Brainard Lake Road en route. The trail takes a two mile loop to the west to avoid a swamp, then drops another 500 feet to the Beaver Bog Road over the next two miles before climbing over a small ridge to the Beaver Reservoir Road. The Sourdough Trail then wanders over more gentle terrain past Beaver Creek for a mile and then drops steeply 400 feet to the Middle St. Vrain in the last mile.

The trail heads north from the Sourdough Trailhead and climbs gently, sometimes on old jeep trails. It climbs more steeply up a small ridge, closely paralleling the Niwot Ridge Road. Then it circles away, climbing more gently on another old road. After crossing Fourmile Creek on a wide bridge, it climbs a couple switchbacks on a narrower trail to the trail's highest point. The Sourdough Trail roughly follows the elevation contour for more than a mile, then dips down to the Red Rock Trailhead, passing the Little Raven Ski Trail at the bottom of the hill.

Continuing north from the Brainard Lake Road, the trail continues to generally drop elevation. It crosses South St. Vrain Creek on a another wide bridge and intersects with the South St. Vrain Trail #909 on the other side. The official Sourdough Trail follows the South St. Vrain Trail for a mile to the left (west), then heads north and then east. It passes north of a meadow with several small ponds. The Wapiti Ski Trail turns off to the north (there are two trail junction signs there but the older one pointing to the west never was a trail), but it does not have a maintained summer hiking trail.

A shorter cut-off trail follows the South St. Vrain Trail a quarter mile to the right (east), then turns off to the left (north) and climbs very steeply before flattening out and hitting the main Sourdough Trail, cutting off two and a half miles of the other trail. From the junction with the cut-off, the Sourdough Trail descends, then circles, then takes a long switchback, and the Baptiste Ski Trail continues ahead at the point. The Baptiste Ski Trail connects to the Wapiti Ski Trail but it also doesn't have a maintained summer hiking trail. The Sourdough Trail drops to cross NFSR 113 at the Beaver Bog Trailhead. An alternate ski route crosses NFSR 113 higher up. The main Sourdough Trail climbs an open hillside in the area of the 1988 Beaver Lake Fire. The main trail and the ski bypass rejoin at the top of the hill, pass through another corner of the burn area, then drop down to County Road 96, east of Beaver Reservoir at the Beaver Creek Trailhead.

The Sourdough Trail continues on the other side of the Beaver Reservoir Road, first more gently across Beaver Creek, then down some short but steep hills, passing the junction with a cut-off that comes into the Coney Creek Road just north of Beaver Reservoir. It drops down some more steep switchbacks to come into the Buchanan Pass Trail near Camp Dick. The official Sourdough Trail continues north 100 yards west on the Buchanan Pass Trail and comes to the south loop of Camp Dick Campground in another 100 yards. However, there is no parking here, so you may want to avoid a third of a mile of road walking by turning left (west) for a half mile on the Buchanan Pass Trail. The Buchanan Pass Trailhead is 150 yards to the right (east) on the 4WD Middle St. Vrain Road.