"Peakbagging" is the obsessive quest to "bag," or summit, high mountains. In Colorado, the highest mountains are the so-called "fourteeners," 54 peaks topping out higher than 14,000 feet. Each summer, people flock to Colorado's fourteeners, and as a newspaper in Colorado Springs described it, it's "like collecting baseball cards: Once you've attained one, you want to gain the whole set."