Kody Malmborg, Jr. drove the first four-stroke snowmobile over the top at the Jackson Hole World Championship Hillclimb put on by the Jackson Hole Snow Devils.

He did this on a Yamaha FX Nytro MTX.

This is the first four-stroke to do so in the 37 years the event has been held.

In all, out of nearly 500 entries, only 60 or 70 made it over the top.

The Jackson Hole World Championships presents itself as a nearly vertical face of about a half-mile in length, with 28 gates that the machines and drivers have to negotiate on the way up.

"It's basically like driving up a skyscraper," said Yamaha snowmobile marketing manager Wade West.

Friday was reserved for Semi Pro finals and Stock qualifying - with Saturday scheduled for the big-horsepower modified and Pro sleds, and Sunday reserved for the Pro finals.

The conditions were so challenging that Malmborg was making it just past halfway up during most of the classes he had entered.

"The course conditions on the bottom half were slushy, and the top was really icy with rocks and stumps, five-foot ruts and six-foot trenches," Malmborg said. "When I left the gate everything felt great, and I just told myself to stay calm and work through every gate, look ahead and pick my lines, use the trenches to my advantage and carry my momentum. I was definitely exited to make it over the top of one of the most challenging hills anywhere. There was definitely some hollering going on!"

In Sunday's Pro finale, Malmborg finished eighth among the world's 25 top hillclimbers after encountering a few problems on his way up the course.