The Big BO 50k 2026

**PLEASE NOTE IF YOU REGISTER AFTER 9/22, WE CANNOT GURANTEE MEDAL OR SHIRT** Stay Obsessed. and the B&O Trail Association are proud to welcome you to the First Annual Big BO 50K Ultramarathon Join your fellow run obsessed friends on the newly completed B&O Trail for a fast, exciting 50K experience unlike any other in central Indiana. The journey begins at Daredevil Brewing Co. in the heart of Speedway — the Racing Capital of the World — and covers the entire length of the B&O trail through Marion and Hendricks County. You’ll Head east toward downtown Indy for a few miles before turning around head out to rural Hendricks County before making the return trip back to Speedway. This course is flat, fast, and built for big goals. Whether you're dipping your toes into the world of ultrarunning for the first time or chasing a shiny new 50K PR, the Big BO 50K delivers the perfect stage to test your limits. Stay Active. Stay Healthy. Stay obsessed.