Hal Koerner and Mike Wolfe are both experienced ultra-distance runners with plenty of 100-mile races under their belts. But neither of them had done anything like their expedition to set a new record time on California’s 220-mile John Muir Trail. For nearly four days, the two took on the elements, nearby forest fires and 84,000 feet in elevation changes in an epic adventure that pushed them to their limits.

Their adventure is chronicled in a new film that’s part of the North Face’s Never Stop Exploring Series. Filmmaker JB Benna joined the pair and the resulting movie will make its debut in Chicago at the ShowPlace ICON Theatre, 150 W. Roosevelt Road, on Sept. 25 at 7:30 pm. Koerner, Wolfe and Benna will be there for a free post-show reception at Fleet Feet Sports in the Roosevelt Collection, which will also include beer from Goose Island and food from Kitchflix.

Movie tickets are available for $10 in advance at www.thenorthface.com/speakerseries and a limited number of free general-admission tickets, which do not guarantee seating, are available online on a first-come, first-served basis. The event, part of The North Face Never Stop Exploring Speaker Series, supports the nonprofit Leave No Trace, which educates outdoor communities about enjoying nature respectfully and responsibly.

Wolfe and Koerner navigating the John Muir Trail during their record-setting run. Mike Wolfe

Mike Wolfe talked with RootsRated to discuss the film and the epic run.

What inspired this epic run?

Honestly, it was Hal’s idea. But both of us had wanted to do some FKT (fastest known time) event like this. Hal had been thinking of the John Muir Trail for years, and he asked me to do it with him.

Had you run with Hal before in something like this?

We just knew each other from racing and we had been teammates for about two years at that point. But we had never run like that before, we’d just raced each other.

You’ve done lots of 100-mile races and ultra-endurance events. How was this expedition different from other races that you’ve done?

The longest I had run and raced up until that point was 100 miles. So trying to wrap your head around going twice as far takes a different kind of effort. There are just so many other variables when you’re on your feet for that long. How much or how little do you sleep? It’s very remote, so how do you figure out crew and how are you going to get food? And neither of us had ever set foot in any section of the trail, so it was new to us. You’re up there, literally at 10,000 to 14,000 feet for like 100 miles of the route. You’re more or less at 10,000 feet or above almost the whole time. Then you’ve got elevation. We did it in August so you’ve got heat. The sun was a factor. Basically it comes down to being exposed (to the elements) for three to four days, as opposed to a 100-mile race where you’re on your feet for 24 hours tops. So it’s very different.

Were above the tree line for most of the route?

Oh yeah. Just being out there in the sun all day long actually took quite a toll on us— more so than I thought it would. You’re among the trees at some points, but a lot of it you’re just on exposed rock high above tree line.

The John Muir Trail. Matt Lavin

Was that the toughest part for you?

Man, there are so many difficult parts. The sleep deprivation began to wear on us a lot. The other thing is—and I don’t want spoil the story for the movie—but we kind of had a snafu at mile 130 with one of our crew and we ended up missing them. So we had to go like 80 miles without crew support, no sleep and we ran out of food. That was the biggest setback for us, which put us in a hole and made the last part of the route really hard.

Was the film crew following you around most of the time?

No, they only met us at these key locations, where we would stop and eat and resupply our packs with food. At a couple of the places when we met the crew they’d also have sleeping bags with us so we could stop and rest. We didn’t carry sleeping bags or anything with us.

Looking back, how do you view the achievement now?

Both Hal and I have raced a lot over the years and done a lot of challenging 100-mile races. You think you’ve maybe pushed yourself as hard as you possibly can or you’ve realized what your limits are. You’ve learned a lot about yourself that way. But I would say, in retrospect, in even in the hardest 100-mile race, I’ve never pushed myself as hard as I’ve had to on the John Muir Trail to finish. It was a whole new revelation or mind-blowing experience in how deep you have to go to pull something like that off. It was certainly one of the best adventures I’ve ever had.