Mark Twain 100/50 Mile Endurance Runs

The Mark Twain Endurance Runs, presented by the Saint Louis Ultrarunners Group, are in their 6th year. We provide excellent aid and a great venue with generous time limits to provide both the most veteran of runners and first timers a great experience. 

The course is a 99% single track trail race with held in the Mark Twain National Forest outside Berryman, MO on the Berryman Trail located about 1.5 hours from St. Louis, MO. The Berryman Trail is a 25+ mile loop that will be repeated 2 (50 Mile Run) or 4 times (100 Mile Run) counterclockwise. Each loop starts and stops in the Berryman Campground where you and your crew/family are welcome to stay and camp at no cost. 

The Berryman Trail traverses many Ozark hills and features long, sustained climbs and fast, rocky descents. The trail is customarily divided into 2 parts; the western 14+ mile section between Berryman Campground trailhead and the Brazil Creek Campground trailhead, and the eastern 10+ miles from Brazil Creek back to the Berryman Campground which completes the loop. The Ozark Trail makes use of the western part of the loop from where it joins it at Harmon Spring, to just west of the Berryman Campground. The Brazil Creek to Berryman Campground section has numerous climbs and descents, none of them really steep, which cross several valleys. This section is also quite rocky with many exposed roots. The western section, while longer, generally contains less climbing, but isn't necessarily easier.