Part of the trip was flat like the second picture, some rugged like the first. I dug through quite a few pictures and there's a lot of pictures of single wagons with horses. The oxen double tandem may have been the Cimarron cut off or later when the were hauling bigger loads, much of which was going to Mexico city, through Mexican traders in Santa fe. There were stage coaches also.
I'll bet this picture was leaving Ft Dodge where the trail splits Cimarron left, mountain right.
