There's a famous canyon in Arizona, I've never been there but I hear it's grand. This photo is of a Grand Canyon, albeit not the one in Arizona. Called the Grand Canyon of Yellowstone, it is located surprisingly enough in the Yellowstone National Park in Wyoming (that's the Yellowstone River running through it). The canyon is roughly 24 miles long and features two large waterfalls (this shot was take from the top of the Lower Falls looking downstream).
Much of Yellowstone National Park lies within the caldera formed 630,000 years ago when the supervolcano beneath the park last had a major eruption. The Grand Canyon of Yellowstone is within that caldera and you can definitely tell that the volcanic activity is still going on beneath the surface. The air in the canyon is fragrant with the aroma of sulfur, steam randomly rises from the ground in various places (the mist in the foreground is from the waterfall rather than steam due to volcanic activity), and the rock and soil are discolored from fluids that have percolated up to the surface over millennia (they've actually chemically altered the rock/soil over time) .
Although it may not be THE Grand Canyon, this canyon definitely is grand, if you get the chance be sure to check out the sights (and smells) there!