Mystery Mountain Marathon & 12-Miler
Chatsworth, United States • 18 Oct 2026
Mystery Mountain Marathon and 12 Miler
The event comprises a marathon and a 12 mile trail race held on and around Fort Mountain at Fort Mountain State Park in Chatsworth, GA. The marathon route includes about 5,500 feet of elevation gain. Trails range from single track and rocky, rooty sections to rugged mountain bike and smoother horse trails.
Both courses start with a loop around the lake and use the Big Rock and Gahuti trails. The route passes a narrow summit loop and a low rock wall that researchers estimate was constructed around 500 AD. Marathon runners follow an additional 301 loop that passes through pine and scrub laurel thickets, upland hardwood and cove forests, old mines, waterfalls, rhododendrons, and a ridge top before returning to the lake.
Course markings use a combination of flags, tape, chalk, and arrows with confidence markers every 2 to 5 minutes. 12 mile runners follow orange markings; marathon runners follow orange for the first section and blue after the Power Line aid station. Aid station coverage:
- 12 mile: three aid stations plus one fluids only station.
- Marathon: six aid stations plus two fluids only stations.
Cutoff times are enforced for safety: the 12 mile has a 6 hour limit with an early cutoff near the park entrance; the marathon has an 8 hour limit with multiple intermediate cutoffs. Bears have been sighted on portions of the course. The race is organized by a nonprofit and a portion of proceeds supports Fort Mountain State Park. Postrace food and beverage are provided. Visit the organization's website for the most recent information.