LINCOLN COUNTY - Tucked away at a small recreation area near Gleason, mountain bikers push themselves to the physical and mental limits every summer.
Earlier today, over 100 riders rode their mountain bikes through 100 miles of trails for the annual Thunderdown in the Underdown.
The 33-mile loop of the Thunderdown in the Underdown is pretty unique.
"Probably the most technical course that I've ridden, outside of going out west to Colorado or some of the stuff up in Canada," said one of the riders, Justin Lund from Tomahawk.
On that 33-mile loop, mountain bikers will see plenty of different land marks.
"Four lakes, climb 64 hills, they're going to go by the Manthei Marsh and pass the Prairie Dells," said race organizer and rider, Chris Schotz.
Simply put, the Underdown Recreation Area in Lincoln County is unlike anything else in the state.
"There are some things here that they won't see anywhere else," said Schotz.
Riders have the choice of doing the loop once, twice, or the few bold ones that do it three times, for a total of 100 miles.
"Make sure you're drinking enough out there, make sure you're getting enough calories coming in because that will get you into trouble before your technical riding ability does," said Lund.
The event has been a part of the Wisconsin Endurance Mountain Bike Series for about 12 years. And it's come a long way since it started with a much shorter trail.
"Probably 10-12 miles, nothing very big, but very, very challenging and that hasn't changed over the years," said Lund.
Another thing that hasn't changed over the years is the respect the riders gain for each other after 10 hours, sometimes more, of riding.
"Whether you're competitive or just here to have a good time, you definitely respect each other out there," said Lund.