146 people are racing 135 miles across northern Minnesota in subzero cold

INTERNATIONAL FALLS, Minn. (FOX 9) - The Arrowhead 135 is recognized as one of the 50 toughest races in the world, and it got even tougher this week as Minnesota braces for its coldest temperatures in nearly 25 years. The 135-mile endurance race is a "human powered ultra-marathon taking place in the coldest part of winter in the coldest city in the lower 48 states," with racers going from International Falls to Tower, Minnesota on bicycle, skis or foot.

Arrowhead organizers call it the "historically coldest gosh darn race anyplace," adding "we have frostbite to prove it."

Monday morning, the temperature in International Falls was -9 with a wind chill of about -23. In other words, perfect weather for the Arrowhead 135.

"They come here for a hard, cold race," race director Ken Krueger told FOX 9. "That's why they are here."

We talked to Krueger from the first checkpoint, 38 miles into the course.

"It's on the Arrowhead snowmobile trail in the coldest city in the United States at the coldest time of the year," Krueger said. "Participants go 135 miles run, bike or ski. There are three checkpoints along the way, otherwise they receive no support whatsoever. One of the checkpoints only provides water."

Krueger has run the race nine times himself and calls it a life-changing experience.

"It pushes you to your limits," Krueger said. "You find out what your limits are and what you are capable of. About 70 percent of our racers are returning racers. We call them veterans. So about 70 percent come back, many, probably over ten times have been here over 15 years, so we have many people that come here year after year after year."

They come and they race because of the cold, all for bragging rights in a race like no other.

"It's almost like if you get a warm year, it's almost like you got cheated," Krueger said.

Not everyone finishes the Arrowhead 135. When we checked in with Krueger on Monday afternoon, five people had already dropped out. He suspects that by the time the race ends Wednesday night, fewer than half of the 146 participants will finish.