It is 18 miles.
The Grand Canyon is a "gorge" or "canyon" if you wish. Hence the name Grand Canyon. However, there are two "plateau's" on either side of the canyon which could be considered part of the GC, from a certain point of view.
i don't know if this is the answer your looking for but John Powell explored the grand canyon at one point.
1.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000km
The highest point at the Grand Canyon is the Kaibab Plateau at 9200 ft. North Rim averages 1500 hundred ft higher than the south rim. It's 6000 ft, or 1 mile deep. 277 river miles long, a million and a half acres. Narrowest point is 4 miles across, widest is 18 miles across right in front of the lodges in Grand Canyon Village. It averages 10 miles across. It is dammed at the top by Glen Canyon Dam forming Lake Powell, and at the bottom by Hoover dam forming Lake Mead.
At its deepest point it is over a mile.
right by the mather point
Point Imperial - At 8803' it overlooks the painted desert of the east end of the Grand Canyon. Point Imperial, the highest point of the Grand Canyon, is 6600' above the Colorado River. There are great views of Mt. Hayden from this view point. Marble Canyon can be seen as well as Saddle Mountain. Location: N. terminus of the Point Imperial road
Yes, the Canyon floor is about 2,600 feet above sea level.
I dont believe any tribe inhabits the Grand Canyon itself at this point but there is a reserve just south of the grand canyon that is home to the Hualapai Indian Tribe. but there may be a few others that inhabit the area.
A canyon is formed by a river. The river rises to the highest point and starts to carve. Then from there the water level goes down... And there's your canyon:-p
Clarendon, Texas
At its deepest point, it is 19,714 feet.