I dunno... The composition on these seems to be a bit off. For example, in number three, you have a couple of rocks and a footprint. The rocks seem to play with my eye for attention and distract me from the footprint. This is particularly true for the rock on the left. Just seems a little jumbled to me. In a shot like this, I want to look at it and immediately know what's going on in the frame and have my attention drawn to the main focus of the shot. Graphical images, such as this one, demand that kind of simplicity to make them successful, IMO.
Not trying to dis' your photo. I think that otherwise, it's very nice and has some mood. Since you live in S.D., it shouldn't be too difficult to reshoot this. If you do decide to do this, I'd love to see you post it here again.