The Bighorn Mountain Trail 100 is an epic mountain endurance adventure crossing through Little Bighorn and Tongue River areas of the Bighorn National Forest. Participants have 34 hours to navigate this remote, technical out-and-back course (average 2.94 mph). Mother Nature provides over 20,500 feet of ascent and 20,750 feet of descent testing the most seasoned ultra-runners with 76 miles of technical single-track trail, 16 miles of rugged 2-track jeep trail road, and 8 miles of gravel road. The Bighorn 100 is one of the classics, demanding you to reach deep down to your core of mental and physical fortitude.