The great canyons of the national parks are for most, drive-to jaw-droppers that lie below scenic drives and rim trails that lead to stunning overlooks. For some, though, canyons beg to be explored. Canyon hikes can be quite an undertaking—almost always a steep, dry descent and a climb back—but the sensory experience is worth it.

   Yellowstone National Park, Wyoming

 

Yellowstone National Park, Wyoming [crystalinks.com]

Located in northwestern Wyoming, Yellowstone seems to contain every type of natural wonder on Earth, so it's no surprise that a magnificent canyon is among them. The 20-mile-long, 1,000-foot-deep, V-shaped Grand Canyon of the Yellowstone is both a thermal area and a river canyon. It was at one time covered by rhyolite lava flows, and some geysers and hot springs are still evident here. An unusual trail leads to the bottom of the canyon at Lower Falls. Uncle Tom's Trail was built in 1898 as a tourist attraction—"Uncle" Tom Richardson built stairs and used rope ladders to get tourists down to the base of the waterfall. The trail is much improved, but still strenuous—it switchbacks steeply and uses more than 300 metal stairs in the course of a 500-foot drop that delivers hikers to the base of the roaring 308-foot waterfall. Distinct colors in the canyon walls indicate thermal spots where the rock has essentially rusted. The park's nominal yellow stone indicates the presence of iron.