The Big BO 50k
About this race
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.
Pick your distance
Running
50k
4:00 PM Cutoff Time.
25k
10k
5k
Typical race-day weather
Based on 4 years of historical conditions on this event's race dates in Indianapolis.
Course
Route map and elevation profile
No course map published yet.
The organizer hasn't released a route for this event, and we don't publish guesses. If you're the organizer, send us a GPX file and we'll draw the profile.
Reviews
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Different organizers, within 40 miles, in the next three months
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🏃 Plan Your Next Race in Indianapolis
Find upcoming events by distance:
- Indianapolis 5K Races 77 races
- 10K Run Events in Indianapolis 18 races
- Indianapolis Half Marathons 14 races
- Indianapolis Running Calendar 2026 98 races
Where this page comes from. Race details were last updated on . We re-check listings regularly and again in the week before race day.
- Entries, prices, waves and inclusions — the event's official registration page
- Temperature and humidity — Copernicus ERA5 reanalysis via Open-Meteo (CC BY 4.0)
- Elevation and terrain relief — Copernicus DEM GLO-90, ESA (CC BY 4.0)
- Comparisons and counts — Race Discovery calendar, 105 Indianapolis events
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