Yellowstone  is best known for its geysers and animals, but for many visitors the Grand Canyon is the park’s most memorable feature. This 20-mile-long canyon ranges 1,500-4,000 feet across and has colorful yellow, pink, orange, and buff cliffs that drop as much as 1,200 feet on either side. The river itself tumbles abruptly over two massive waterfalls, sending up a roar that’s audible for miles along the rims.
Grand Canyon is accessible by road from both the north and south sides, with equally amazing views. The lodgepole pine forests around here escaped the 1988 fires.
After a massive volcanic eruption 650,000 years ago, rhyolite lava flows came through what is now the Grand Canyon. The flows eventually cooled, but geothermal activity within the rhyolite weakened the rock with hot steam and gasses, making it susceptible to erosion.
Through the centuries, a series of glaciers blocked water upstream, each time creating a lake. As each glacier retreated it undammed the stream, allowing the water in the lake to empty suddenly. The weakened rhyolite was easily eroded by these periodic floods of water and glacial debris, thus revealing pastel yellow and red canyon walls colored by the thermal activities.
The Lower Falls are at the edge of the thermal basin, above rock that was not weakened by geothermal activity. The Upper Falls are at a contact point between hard rhyolite that does not erode easily and a band of rhyolite that contains more easily eroded volcanic glass. Today the canyon is eroding more slowly, having increased in depth just 50 feet during the last 10,000 years.
A one-way road takes visitors to a series of extremely popular overlooks along the north rim of Grand Canyon of the Yellowstone. Farthest east is Inspiration Point, where the views of the canyon and Lower Falls are, well, inspirational. A wheelchair-accessible canyon view is available from the edge of the parking lot. North Rim Trail leads along the rim from Inspiration Point up to Chittenden Bridge, three miles away, and some sections of this scenic and nearly level path are paved. Just a couple of hundred feet up from Inspiration Point, be sure to look for a 500-ton boulder deposited by a glacier during the glaciation that ended 15,000 years ago. The glacial erratic (as such rocks are called) originated in the Beartooth Mountains at least 30 miles north of here and was carried south atop a moving river of ice.
The one-way road continues westward to overlooks at Grandview Point and Lookout Point. From Lookout Point, a 0.5-mile trail drops 500 hundred feet to Red Rock Point for a closer view of Lower Falls—you can feel the spray. Farthest west along the one-way North Rim Road is the trail to the Brink of the Lower Falls. The trail is 0.5 mile long and paved, descending 600 feet to a viewing area where you can peer over the edge as the water plummets in a thunderous roar over the 308-foot precipice (twice the height of Niagara Falls). This is probably the most breathtaking sight in Yellowstone, but if you suffer from vertigo don’t even think about peering over the brink! Just south of where the one-way road rejoins the main highway is a turnoff to the Brink of the Upper Falls, where a short walk leads to a less dramatic but still beautiful view of the 109-foot-high Upper Falls.
A party of prospectors wandered north into this country in 1867, following the Yellowstone River downstream without suspecting the canyon below. A. Bart Henderson wrote in his diary of strolling down the river and being:
Very much surprised to see the water disappear from my sight. I walked out on a rock & made two steps at the same time, one forward, the other backward, for I had unawares as it were, looked down into the depth or bowels of the earth, into which the Yellow plunged as if to cool the infernal region that lay under all this wonderful country of lava and boiling springs.
Canyon Village on the north rim is a forgettable shopping mall in the wilderness, complete with various stores and eating places, a post office, a gas station, cabins, lodges, and a campground. It’s a good place to come on a rainy summer afternoon when the kids are starting to scream for ice cream. Horseback rides are available less than one mile south of here.
The real attraction at Canyon Village is the recently opened Canyon Visitor Education Center (307/242-2550). This must-see stop has fascinating exhibits detailing park geology, from geysers and hot springs to the supervolcano that powers everything. A room-size relief model illuminates the park’s volcanic eruptions, ashfall, lava flows, and glaciers. Kids can turn the 9,000-pound rotating globe to find volcanic hot spots, and a giant lava lamp illustrates how magma rises in the earth. Upstairs, check out exhibits on earthquakes, including a seismograph showing today’s temblors. There are all sorts of other high-tech exhibits, plus exhibits on lodgepole pine forests and grassland habitats. You could easily spend an hour here and will certainly come away with a better understanding of Yellowstone’s inner workings.
The visitor center is open daily 8 a.m.-8 p.m. June-September and 8 a.m.-5 p.m. in May and September-mid-October. It’s closed in winter.
The south rim of the canyon is lined with dramatic views into Grand Canyon. Cross the Chittenden Bridge over the Yellowstone River (otters are sometimes seen playing in the river below) and continue 0.5 mile to Uncle Tom’s parking area, where a short trail leads to views of the Upper Falls and Crystal Falls. More unusual is Uncle Tom’s Trail, which descends 500 feet to Lower Falls. The trail is partly paved, but it’s steep and includes 328 metal steps before you get to the bottom—good exercise if you’re in shape. It was named for “Uncle” Tom Richardson, who, with the help of wooden ladders and ropes, led paying tourists to the base of the falls around the turn of the 20th century. Because there was no bridge, Uncle Tom also rowed his guests across the river near the present Chittenden Bridge. After his permit was revoked in 1903, visitors had to make do on their own.
One mile beyond Uncle Tom’s parking area, the road ends at the parking area for Artist Point, the most famous—and crowded—of all Grand Canyon viewpoints. A short paved path leads to an astoundingly beautiful spot where one can look upriver to the Lower Falls or down the opposite direction into the canyon. Look for thermal activity far below. The point is apparently where artist Thomas Moran painted some of his famous watercolors. Avoid the crowds and afternoon thunderstorms by getting here early in the morning; it’s almost always deserted at sunrise.