Looking at this picture, it is hard to guage the depth to the bottom of the gorge. I estimate it was several hundred feet at a minimum.

  The cliff face on the left side of the picture really gives a good indication of the steepness of the canyon walls.

  This is a really good shot of the stratification in the local sediment. It is interesting how the thickness of the different levels is so consistent. If this stratification happened over such a long period of geological time, I would expect a much larger variation in the thickness. This appears to me as if some kind of cyclical and periodic process deposited the layers. Yet, there would have to have been enough time between the depositing of each layer for the boundary edge between each layer to form before the next deposit. One more thing for my list of things that make me go, "Hmmmm...."

  Notice how the landscape behind the bikes is basically flat and open. Imagine your wagon train expedition coming upon this huge expanse of easily traversed landscape and thinking to yourself, "at last, we can make some good time over this easy landscape...", and then you come upon this gorge... DOH!