North Fork 50
The North Fork 50 Mile/50K is a gem of an ultramarathon in the Colorado mountains just southwest of Denver. The course is 100% soft surface, made up almost entirely of incredible singletrack trails with a few short sections of double track road.
Climb through open burn areas from a 1996 fire, then dive back into the beautiful ponderosa pines and wind around towering granite rock formations as you excite your senses and challenge your mettle.
A portion of race proceeds goes to the North Fork Volunteer Fire Department, which supports and serves the local community.
*Distances may vary slightly each year due to permitting.
Start Times
Saturday, May 3150 Mile - 6:00 am
50K - 7:00 am
Bib Pickup
Buffalo Creek Clubhouse18050 S Buffalo Creek Rd
Buffalo Creek, CO 80470Saturday, May 31
5:00 am - 7:00 am
Volunteer
We need help to make North Fork possible. Volunteer perks include Aravaipa race credits, race tee and food/drink at the finish line festival!Bear Chase Race Series
North Fork Ultras is part of the Bear Chase Race Series. Take on some of the flowiest, butteriest, amazingest, and funnest singletrack in the region across four exciting events: Rock Hawk Trail Races, North Fork 50, Chase the Moon, and the Bear Chase.Live Tracking
Follow the 2025 North Fork 50 with live split points throughout race weekend.Race Registration
Until 12/16 | Until 3/31 | Until 5/26 | Race Day | |
50 Mile | $165 | $180 | $195 | $210 |
50K | $140 | $155 | $170 | $180 |
Course Information
Start Time | 6:00 am
Time Limit | 14 Hours (8 pm)
Distance | 50 Miles
Total Elevation Gain | 6,425 feet
Max Elevation | 8,535 feet
Women's Course Record | 8:30:21 - Elizabeth Gold (2017)
Men's Course Record | 7:17:58 - Michael Hewitt (2017)