Oh, this is awesome! I love some of the little touches, like the river "wandering away" (snake-like) toward the end, and the appearance of the canyon too. I must admit though I watched it at 2x speed, it was just a bit too slow to fully keep my attention otherwise. I bet you may be able to halve the number of frames rendered and use some decent interpolation filter in a video editor to get similar-looking, slow, smooth motion at this same speed, but in half the render time...
In any case, very cool!
- Oshyan