Somewhere in the Rockies, in the roughly 1,000 miles between Santa Fe, New Mexico, and the Canadian border, may be a treasure chest worth millions. The man who claims to have hidden the fortune back in 2010 is Forrest Fenn, now 87, a former Vietnam fighter pilot and art dealer.

Fenn estimates that as many as 350,000 people have gone hunting for the treasure, he tells CNBC Make It, adding that there is no way of knowing whether anyone has actually gotten close. "It could be found soon or 1,000 years from now," he says.