The bulk of the formation is composed of siltstone and claystone redbeds.
Pictured are the tops of the individual beds. The 1 cm bars are accurate, to show scale.
A few months after dropping some specimens off with the Oklahoma Geological Survey, they told me that there were probably "arthropod locomotion marks". Being busy with life in general, I accepted the answer without trying to determine "what sort of arthropods".
Recently, while looking at some of the slabs, I revisited a point of previous curiosity. Each trackway seemed to not have a companion for the opposite side of the critter. Perhaps because the critter was wider than the slab of rock.
So I started doing an internet search of Permian arthropods. An early result gave the word "Arthropleurid" as a likely suspect. An Arthropleurid was a large, centipede-like critter, in some cases up to 6 feet long. A later result gave this article, concerning the Late Pennsylvanian Cutler Group, in northcentral New Mexico.
If I get a chance to revisit the area, I will be looking for wider slabs, to hopefully find more-complete trackways and to document the occurrence a little better. Would like to maybe do a short paper/talk, maybe for a future GSA regional meeting. Or if I don't, maybe I will have somehow inspired someone else (in Oklahoma) to do so.
[The comments were generated with the original 2007 post.]