The Oak Ass 100/50 serves as the championship finale for the National Ultra Endurance Series, drawing amateur and professional mountain bikers to Oak Mountain State Park’s challenging Alabama terrain. As the season-ending showdown, this race carries extra weight for riders chasing overall NUE rankings and creates an electric atmosphere where months of training and racing culminate.

Riders tackle either a demanding 50-mile single lap or the full 100-mile double lap on the park’s legendary Double Oak Trail system. This IMBA Epic-designated course weaves 22 miles of purpose-built singletrack through 9,940 acres of diverse terrain, combining technical rocky climbs with the park’s signature Lightning Flow Trail descents. The course demands both grinding endurance for sustained climbs up Johnson’s Mountain and precise bike handling through technical sections before rewarding riders with fast, flowing singletrack.

Oak Mountain’s trail system stands out in the Southeast for its year-round ridability and thoughtful design that tests every aspect of mountain biking skill. The course features significant elevation changes that separate contenders from pretenders, with steep climbs followed immediately by technical descents that punish tired legs and foggy decision-making.

The championship atmosphere sets this event apart from typical NUE races. Riders arrive having battled through the season’s earlier events, and the stakes feel higher as series titles hang in the balance. Aid stations are strategically placed to support the technical demands of the course, while strict NUE time cutoffs maintain the event’s reputation as a true test of ultra-endurance capability.

Veterans consistently praise the course’s perfect balance of technical challenge and flowing rhythm, noting how it rewards both power and finesse while delivering one of the most complete mountain biking experiences in the country.