The Grand Canyon is not the longest, widest, or deepest canyon on Earth, but as the only canyon among the seven natural wonders of the world, it’s arguably the planet’s grandest canyon. So what makes it so grand? And how long do geologists expect it to retain that honor?
As it flows across northwest Arizona, the Colorado River and its dozens of tributaries have carved a wondrously intricate rainbow of interconnected canyons. From overlooks on the North and South Rims of Grand Canyon National Park, the views are unfathomable.
To have any hope of grasping the enormity of the landscape and how it was carved by water, however, you have to descend below the rims.
The Grand Canyon is one of my favorite backpacking destinations. Trails from the rim to the river lose 1,500 meters of elevation, taking you back in time from the 230-million-year-old Kaibab Limestone on the rim to the 1.7-billion-year-old Precambrian basement rocks along the river. The geologic layer cake is so rich that as you descend, every downward step moves you tens of thousands of years backward in geologic time. (Of course, then you have to hike back up through all that history too.)