Sourdough Trail Marathon

Mission: The Sourdough Trail Marathon was created to bring together the Boulder County trail running community to recognize and support the local organizations that maintain and protect our beautiful public lands we have the privilege to explore.

No Race in 2019.  Event will return next year, September 2020!

Register Here

Race Information: 

Date: September ?, 2020 (Race not being held in 2019.)

The race field will be limited to 70 runners to abide by U.S. Forest Service regulations.

Race Start Time: 7:00 AM  (7.5  hour cut-off time)

Race Start/Finish Location: Google Maps Link

South Sourdough Trailhead

115 County Road 116, Nederland, CO 80466

Cost: FREE!  However, donations will be accepted at packet pick-up.  100% of all donations received will go directly to the Indian Peaks Wilderness Alliance.  They are one of several non-profit organizations that steward our local public lands we all love and enjoy for free.

Packet Pick-up: Boulder, Colorado 

At Go Far Shop in Boulder!

Address: 2005 Pearl St, Boulder, CO 80302


Course Information: Approx. 25 miles of rolling trail with 3,800 feet of climb at high-altitude.

The Sourdough Trail stretches nearly 13 miles (south-north) from Rainbow Lakes Road to Camp Dick Campground through Roosevelt National Forest and just outside the eastern border of the Indian Peaks Wilderness. This beautiful rolling trail takes you above 10,000 feet in elevation through dense pine forests of lodgepole, spruce, and fir. The marathon course is simply an out and back along the entire length of the Sourdough Trail, starting and finishing at the South Sourdough Trailhead. Runners will turn-around at the intersection with Buchanan Pass Trail, which marks the half-way point of the race, and the northern terminus of the trail. The course will be unmarked in a sense, because we will not be adding any markings, but all trail intersections have been marked by the forest service with wooden signage (always follow signs for Sourdough Trail 835).  This is a ‘Leave No Trace’ event, because it is important to us that we do not add any pollution to the forest, and demand the same ‘Leave No Trace’ practice from all of our athletes.  There will be 2 aid stations along the way that you will visit each twice (once on the outbound and once inbound) at approximately miles: 6, 11, 14, and 19.

Sourdough Trail Marathon Course Map (Printable PDF)

Here is the link to the course segment on Strava

For now, you can learn more about the trail and download a map with trail profile provided by Trail Run Project here:

South Sourdough Trail #835

North Sourdough Trail #835