Thousands of runners will hit the trails, roads and lonely stretches of Northern Utah scenery this weekend in what has become the largest running event in the state and one of the biggest in the country.

The Ragnar Relay Wasatch Back race begins Friday in Cache Valley and will not stop for anything, not even the darkness of night, as teams of as many as 12 runners traverse the Utah back country on a two-day adventure that will test the physical and mental limits of those hoping to complete the race in Park City.

The relay for most participants is a matter of completion rather than competition.

Although some teams are definitely in it to win it, the majority are racing either for a good time or a good cause.

"Anyone who has run the Wasatch Back knows that it's not just about the run, its about the experience," said Tanner Bell, co-founder of the Ragnar Relay series. "There is something incredible about being stuck in a stinky van for 24 hours with your teammates."

The race was born in 2004 with just 22 teams.

Now, the 188-mile journey from Logan to Park City is nothing short of a phenomenon, with similar events popping up across the country.

The Ragnar Relay has grown from 22 teams in Utah to a 10-event organization with a race in Utah and similar events from Florida to Washington, Arizona to Massachusetts and points in between.

This year, more than 9,000 people will run — and that's just in Utah.

"We have the best participants in the world," said co-founder Dan Hill. "Each of them has a different story, a different background, a different running skill level, and a different personality. When you put each of those people in a van together for 24 hours, the most amazing, wacky and inspiring things happen."

Equal parts party and physical challenge, the relay race has ultra-competitive teams made of former college runners trying to beat each other for victory and rag-tag teams of friends, family members and co-workers running for the fun of it.

"It's invigorating to have 11 teammates cheer you on in the middle of the night as you struggle to conquer your second leg," Bell said. "And it's nothing short of incredible to cross the finish line with 11 teammates knowing you accomplished something together that you never could have done on your own."

Registration for the race was once easy. You asked friends and signed up, hoping someone would supply a support vehicle to carry the tired runners from one checkpoint to the next.

Now, if you snooze, you lose. Registration opens months before the event and sells out quickly.

Waiting lists for future races fill fast and 42 states are represented in this year's Utah version of the race.