Fade into the Black Canyon via Colorado's Gunnison River.
Credit: Derek DiLuzio / Getty Images

Two thousand feet straight down in western Colorado's Black Canyon, there's an angry, unrunnable 12-mile stretch of the Gunnison River where the brown and rainbow trout happen to grow bigger than the blade of a canoe paddle. Short of a BASE jump, though, the only way to reach the water - people have died trying to raft it - is via a series of draws, including the ankle-busting, poison ivy-choked SOB Draw, described in guide books as "a controlled fall." (Safety harnesses, helmets, and rope are recommended.)

More information: The Black Canyon is a national park, so no guides are allowed, but the folks at Cimarron Creek fly shop, on Main Street in nearby Montrose, will know what the hogs are hitting. [cimarroncreek.com]