 Well, one way of starting to answer that question is just to consider the idea that there is a highway through the Grand Canyon. It's called the Colorado River. It's the tool that carved and created and polished and honed and sculpted the canyon in the first place. And over the course of its journey through the park, from the eastern end, at least, to the western terminus, it's what's called the Grand Wash Cliffs. The river travels about 277 miles. But if you're on foot, Mary, there are so many side canyons that you must work your way into and back out of