James Nelson, 31, of Chicago bills himself as an experienced back-country hiker.
"I organize trips that tend to be strenuous and involve hiking for an entire day at a steady pace; often over difficult terrain or in challenging weather," Nelson says on the Chicago Backpackers Meetup Group, where he's an Assistant Organizer. "Trips often require hiking 10+ miles. I am also quite knowledgeable about most backpacking gear."
That knowledge now seems to be up against an epic test in the rugged terrain of Colorado's Rocky Mountain range, where there's now a search underway for Nelson.
Nelson was reported missing Friday by his fiance, after he set off alone on Oct. 3, on a five-day, 25-mile hike of Mount Holy Cross in Eagle County.
"While James is an experienced hiker, this is his first hike in Eagle County. James is equipped with proper gear and supplies, but is not carrying a cell phone," said Shannon Cordingly, an Eagle County Sheriff's Office spokeswoman.
Crews started searching for Nelson on Saturday. Over the last two days about 30 community volunteers from Vail Mountain Rescue Group have covered Nelson's proposed route and have found no trace of him.
"At this point, it's a pretty safe bet that, in some way, he got himself into trouble," Cordingly tells NBC Chicago. "The fact that we haven't heard from him since the 3rd isn't ideal."
At 14,000 feet, Mount Cross is one of Colorado's most famous, yet one of its more treacherous mountains. Cordingly says the trails are filled with steep drops and abandoned mines, and that wildlife in the area includes mountain lions and black bears.
She says this mountain is primarily hiked by those who are experienced, and that it's quite uncommon, because of the potential perils, to hike this mountain alone.
Cordingly says Nelson's fiance is in Colorado tracking the search and that family members have started to arrive on scene.
Here in Chicago, Erik Zumbahlen, a bartender at Sully's House in the Lincoln Park neighborhood, was floored to hear about the search for Nelson. For about the last year, Nelson's hiking group has met up at his bar the second Monday of every month to talk over beers about recent trips to the outdoors.
"He's a super nice guy. You hate to hear about that kind of stuff."