People traveled from across the country - Texas, Hawaii - and from across the world - from as far away as Spain and Dubai to push themselves to the limit.
This is the event's third year..and organizers say it's called the Badger Mountain Challenge for a reason.
"This is not a short race - it's not an easy course. There's a lot of areas that are rocky - really sandy. After finishing a race like this, you feel like you can do anything," said Badger Mountain Challenge Organizer Brandon Lott.
The 15 and 50 kilometer runs begin Saturday morning.