The Dirty Kanza is billed at the World’s Premier Gravel Race. The feature event distance is a 200 mile long ultra-endurance bicycling challenge, held on the gravel roads through the Flint Hills region of east-central Kansas. Additional distance options include 100-mile, 50-mile, and 25-mile. Participation is by pre-registration only. Sign-up for the lottery selection opens January 1, 2019.