It's the muddiest race of the year, at the 7th annual Grand Rapids Mud Run.
This year, over 1,500 people are expected to run the course. Every year the course changes, so no one knows what to expect in the muddy race.
The course will be filled with mud pits, a 60-foot mudslide, tunnel crawls, walls, and slippery hill climbs. There's even a mini-run for children who are 6 to 12 years old.
The run is on Saturday, August 27, with the first group of runners taking on the obstacle course at 8:30 a.m.
The starting line will be at 1200 60th Street in Kentwood, next to Celebration Cinemas South.
The adult 5K cost $49 and the kids mini mud is $20. You can get one free kid's registration with the purchase of an online adult 5K registration.
To register to run or be a volunteer, click here.