Today, Challenge Unlimited captains biking and hiking tours all over the globe, from the vineyards of Tuscany to the Incan towns of Peru. More than two decades ago, however, the business was simply known in Colorado for its signature Pikes Peak by Bike tour. During this 20-mile excursion, guides and up to 35 followers descend 20 miles from a summit of 14,110 feet, infiltrating five zones with distinct climates, plant life, animals, and altitude-based baking methods. Riders often encounter eagles, deer, elk, and even the occasional mountain lion or black bear along the way. Guides can also escort Colorado's athletes across the Gold Camp Road—a 17-mile railroad bed once rattling with railcars filled with gold—and through breathtaking Aspen groves. Pit stops are made over the course of three nights and four days at the Victorian Hotel and a nearby dude ranch. Beyond domestic borders, international trips explore Nepal's Annapurna Foothill on foot and the bustling pubs and haunts of Ireland by bike or skateboards strapped to sprinting leprechauns.