Mountain Highs

Thrill-seekers are discovering the joys of zip lines, rides that zoom over treetops at high speeds. Riders wear a harness that clips to a cable, and automatic brakes prevent crashes at the bottom. Popularized in Costa Rica as a way to tour the forest canopy, zip-line rides are popping up elsewhere around the globe.

The newest is at California's Heavenly Mountain ski resort, where riders hit speeds of 80 kilometers per hour and enjoy views of Lake Tahoe ($30; ski On the super-steep zip line at the Utah Olympic Park in Park City, riders can watch Nordic ski jumpers launch from the 120-meter jump that runs parallel ($20; The zip line at Alaska's Icy Strait Point, popular with cruise-ship customers, is more than a mile long. Suspended 162 meters in the air, riders sometimes look down to see bald eagles flying below ($90; The operators of the ProNutro 2000 in Sun City, South Africa, bill their zip slide—as zip lines are known there—as one of the longest and fastest, with riders achieving speeds of 150 kilometers per hour during a three-minute ride ( How popular are these heart-pounding rides? ZipRider ( is building one at a ski resort in Siberia. Hold onto your fur hats!