Welcome to the fray ikester7579.

And yet one distinctive difference between the photo on the left (bottom of canyon) and the one on the right (middle of canyon) is deep vertical lines in the one on the right. Not one exists in the photo on the left. The upper rocks are weathered compared to the lower rocks, weathered in proportion to their distance from the bottom.

Can you explain the difference in weathering by water erosion alone?

Actually, rain falls in the direction of the wind, and the angle depends on the force of the wind. I was in a thunderstorm at Flagstaff AZ, and the rain was nearly horizontal.

Another factor that is known to make vertical cracks in rocks is freeze and thaw cycles where water gets into small cracks and expands as it freezes. This is much more likely to have caused the vertical lines in the rocks on the right than rain.

Yes wind erosion is also part of the answer, because the rock you are seeing on the right is not the rock carved by the water. You can also see the same patterns in areas where there is no water at all - from deserts to other areas of the canyon that are perpendicular to the main flow. This is known to occur, and to ignore it is to ignore part of reality.

You can also see this same pattern of banded erosion on the middle hill in this picture from inside the Grand Canyon - was the water running at a funny angle (uphill?)?:
. . .
(from http://web.mst.edu/~rogersda/cp_megalandslides/grand_canyon.htm which has a full size version, click on the picture to see).

Wind erosion is not just gently breezes blowing through trees, it can be dust filled howling winds that act like sand-paper on all surfaces it comes into contact with. Wind and water are very similar in their effect on rocks, just with different viscosities, and both are augmented by carrying dust and silt and sand particles.

What causes the pattern of indented layers is not the water per se: it is the alternate layers of the rock, as different types have different hardness, even rocks of the same basic type have different densities.

This is why you can see this same pattern or differential wear in the vertical pattern on the rock in your lower picture, the pattern that is aligned with the layers in that rock.

You can also see that the pattern of rock layers in the Grand Canyon is horizontal by the bands of different colored (types) of rock. You can also see that some rock types are quite different in erodability.

Actually, trying to limit erosion to be only (a) from the river and (b) from vertical rain, would be trying to rewrite the "laws" of erosion. It is what is called a "straw man" argument, one that ignores a significant part of reality.

Let me draw your attention to the middle of the right side photo on the right side of that photo: you will see a gray slope below a cliff. This slope is scree, small stones and rocks that have fallen from the cliff as it erodes. The cliff has both vertical and horizontal patterns above the scree (as do other cliffs in the distance).

Now you have a problem: either (a) the river water carved the horizontal patterns (as you seem to claim) but somehow lacked the force to carry away the small rocks that it had the force to wear out of the big cliff, or (b) the rocks at the bottom are from vertical erosion caused by your rain straw man, however then it also carved horizontal bands in the rocks it was eroding. This contradiction shows that your simple straw man is not a complete picture of the erosion in the Grand Canyon.

This pattern of cliffs over scree is also common throughout the canyon, and the presence of these small rocks on the slopes below cliffs cannot be explained by water erosion due to a flooded river: notice the lack of scree at the bottom of the picture on the left: river erosion is characterised by the river removing material and depositing it downstream in low bars.

Weathering - wind, rain, ice - cause scree to fall from cliffs into the slopes below, which build up at angles so steep that they are dangerous to climb: if you dislodge one rock you may cause a rock slide of the whole slope. You also need long periods of time to accumulate scree to the extent that is visible in the Grand Canyon.

Enjoy.