Entertaining but short.
I bought this after buying a 3D TV and looking for something that really showed off the 3D, I have been to the Grand Canyon a bunch of time and will always maintain that you cannot capture the sheer scale of the canyon, even in 3D its still missing the massive scale that is simply breath taking. The film is mainly about the river running through the canyon rather than the canyon itself (clue is in the title!!) but having said that there are still lots of shots of the canyon itself. My 2 criticisms would be that its quite short at 44 mins and the bonus features are not in 3D, that said its still absolutely stunning, the best 3D I have seen so far on my TV and the closest I think we will come to actually appreciating the true glory of The Grand Canyon without actually being there.