Embark on an unforgettable trail adventure at the Mystery Mountain Marathon on October 18, 2026, nestled within the breathtaking Fort Mountain State Park in Chatsworth, GA. This highly-regarded event offers a challenging Marathon (26.2M) and a rigorous 12M race, drawing runners to its difficult, often technical, and stunningly beautiful trails. With typical race day conditions presenting comfortable highs around 73°F and lows near 48°F, and only a 16% chance of precipitation, runners can expect ideal fall weather for tackling the mountainous terrain.

Both distances begin with a scenic loop around a serene lake before venturing onto a mix of single-track, rugged mountain bike, and smoother horse trails. Marathoners will experience approximately 5,500 feet of elevation gain, traversing over and around Fort Mountain with panoramic views of vibrant fall foliage. A unique highlight is the passage by the mysterious ancient rock wall, built over a thousand years ago at the mountain's summit, adding an element of historical intrigue to the demanding course. The marathon course notably includes the Big Rock and Gahuti trails, with the 26.2M distance adding a challenging 301 loop that features waterfalls and old mines.

Run by the Georgia Ultrarunning & Trailrunning Society (GUTS), the Mystery Mountain Marathon is renowned for its excellent organization and supportive atmosphere, providing six full aid stations and two fluids-only stops for marathoners, and three full aid stations plus one fluids-only for the 12-milers. Runners consistently praise the race as "addictive" and a "true trail race," though many acknowledge its extreme difficulty, emphasizing the need for careful pacing on the rocky, root-filled paths. This non-profit event limits entries to 250 combined participants, fostering a low-key, celebratory atmosphere by the lake at the finish, and contributes a portion of its proceeds directly to Fort Mountain State Park.