The Big Mountain Enduro Series and North American Enduro Tour come to Keystone this weekend for two days of downhill-focused racing with a cross-country twist.

“We’re really excited to be hosting a pro-level event,” said Laura Parquette, spokeswoman for Keystone Resort. The race is also open to amateurs and registration is ongoing.

Enduro is a relatively new class of racing that originated in Europe and has grown popular in the northwestern United States.

“It’s exploded here,” said Brandon Ontivero, Big Mountain race director. “We haven’t seen a mountain biking discipline grow like this in years.”

The reason, said Ontivero, is that it is a blend of cross-country and downhill biking disciplines.

“It’s inviting to a broad group,” he said. “The roots came from Europe from a motocross background”

Endro class events run as a series of timed stages that riders access either by lift or untimed transitions.

The end result is courses that are 85 percent to 90 percent descending, but with a blend of cross-country and downhill riding freatures, said Ontivero.

Racers typically ride bikes that are a blend of strictly downhill or cross country setups. Usually a dual suspension bike with around six inches of travel, said Ontivero. That gives competitors the versatility of a bike that can handle technical downhill sections but won’t take away too much pedal power from uphill travel.

Ontivero expects close to 300 pro and amateur racers to participate this weekend. The Keystone event is part of both the five-race Big Mountain Enduro Series, and the seven stop North American Endo Tour. It is the first time Keystone has hosted either event. Both racing series are only a few years old and continue to grow with the rise in Enduro class racing.

The weekend-long events at Keystone will also feature kid-friendly activities in Keystone Village, including live music. Oskar Blues Brewery will be on hand, as well as a number of bike-industry reps in a sponsor village, set up near the gondola. Keystone’s bike park will be closed during races, but will open for free to the public form 5 to 7 p.m. Saturday.

“Come check out the fun,” said Ontivero.