[m741]

You can simply drive to the rim. The entire path around the rim is paved and handicap-accessible. You can take a mule into the canyon. It's difficult to get to only in the sense that you must drive for several hours from any nearby city to reach the area.

[prawn]

Exactly, it's remote but it's not inaccessible. The same is true of Yosemite, Death Valley, Yellowstone, Arches, etc.