[ml/nj]

all those melting glaciers at the ending of the multiple ice ages

Not that I believe in the ice ages, but if there were "all those melting glaciers" and no Grand Canyon, you'd sort of have to explain why the melting water or the ice found its way up to 5000 feet above sea level, and if it was there why it didn't flow downhill like water is supposed to do but instead cut a massive chasm (or really chasms, but that's another problem) in the rock.

ML/NJ

[stormer]

Huh? Water finds “its way up” in mysterious objects called “clouds”. And the process you don't seem to be considering is the uplift of land due to tectonic forces and isostatic rebound; for practical purposes the river stays at the same relative height and gradient while the land raises on either side.

[SampleMan]

The rim of the Grand canyon IS downhill from the Colorado river catch area. Melt water from further north follows that path now, and it followed it before.

Many of the erosion features that make no sense given current water flows suddenly become logical when you consider ice age melt.

The Colorado river has cut canyons all the way up to where it begins. Also when you drive through a river valley that goes south from the glacial areas, you see that the modern river actually winds between ancient river banks that are sometimes miles wide. There are no current flooding levels that come close to explaining those ancient river banks.

[CIDKauf]

Fossil Fish capital of the world is Kemmerer, WY, just south of Jackson and the Grand Tetons...portions of the west were under water completely.