The Mustang Marathon (formerly Hill Country Trivium) is a set of 50k, full marathon, half marathon (a.k.a. “Thirteener”), 10k & 5k races held in the beautiful Hill Country town of Marble Falls. Each race takes place on a paved surface involving a true “Out & Back” course on country roads with rolling hills, formidable climbs and gorgeous views. All races begin and end at the Marble Falls High School’s Mustang Stadium.