Run the West's whitest water.

Rafters didn't muster the courage to paddle Colorado's Gore Canyon until the 1970s, and it's easy to understand why. This chasm on the Upper Colorado is a six-mile gauntlet of fuming Class IV and V rapids over a half-dozen drops, including a 12-footer. Put in with the national rafting champions at Timberline Tours, which runs full-day trips from August through October. Then hang on for one of the hairiest stretches of whitewater in the country. [$85-$190;]