The Marmaton Massacre is an annual mountain bike race on the Gunn Park Trails in Fort Scott, Kansas. The trails wind through a wooded area along the Marmaton River. They are mostly non-technical trails with relatively easy climbs and descents.
Categories include Expert (3 laps), Sport (2 laps), Beginner (1 lap), Marathon (3 hours), Junior (1 lap), and Singlespeed (2 laps).