IRONWOOD, MI - For the first time in nearly 25 years, Michigan's steep ski-flying hill in the Upper Peninsula will host an international sporting event when it welcomes the Red Bull 400 this spring.

But this time, Copper Peak competitors won't need skis or snow.

They'll need strong legs, a lot of grit - and no fear of heights.

Billed as the world's steepest 400-meter race, the Red Bull 400 will have runners going vertical on May 12. They will run up 40 stories - first tackling the hill at the bottom of the ski jump, then running up the jump to reach the top of the world's largest artificial ski jump tower.

"Copper Peak historically is a place where athletes push the limits of athletic ability and break records," said Charlie Supercynski, president of Copper Peak's board, in a message posed on the ski jump's Facebook page.

"We were used to seeing people fly off Copper Peak, not sprint up the jump. This brings a whole new element of competition and a great first event in the start of the revitalization of Copper Peak."

Built in 1969, Copper Peak hosted 10 international ski competitions before it closed in 1994.

Since then, it's been a high-rise tourist draw, giving people a gorgeous 360-degree view of the western U.P.

In 2015, Copper Peak officials said they were drawing up plans to renovate the structure and draw more events.

Registration for the Red Bull 400 is $50 per person. It's limited to 400 people. For information about how to register, check here.

It's one of several vertical races the energy drink company has planned across the world this year.

"The 2018 Red Bull 400 season is set to conquer ski jumps across Europe, Asia and North America, putting racers all over the world under the most grueling physical pressure they'll ever face," the company said. "Warm up your leg muscles and gear up for the hardest 400 meters of your life!"