The Bighorn Race is an unofficial challenge in the Big Horn mountains of northern Wyoming. The third running has a proposed start date of September 6, 2019. It is 350-mile loop course. The riding surface is probably most similar to the Colorado Trail Race, with lots of rocks and roots, but the Big Horn Mountains are geologically distinct from the Rocky Mountains with their own unique spin on the different life zones.
This event is not sanctioned or organized in any way. There are no permits, prizes or entry fees. It is a group of people riding their bikes on the same route at the same time. It is an entirely self-supported race against the clock. No drafting, blocking or other teamwork, no support and no caching allowed.