SEHunter,
I heard this story for the first time on Monday of this week by the fellow guiding me through the Black Mesa area. Wow, what a coincidence. He is a local teacher and farmer, and like his father, grandfather, and great grandfather, he has lived in that area for his entire life. His great grandfather was reportedly the first white child born in Cimarron county (I imagine that it wasn't Cimarron county at that time). Nonetheless, this guy is a realist and pretty concrete. He discussed the elements of the story as if they are indeed fact. In fact, he says there is a German fellow that comes out every 3rd summer or so, and continues to search for the treasure. Two points you mentioned that are correct. The marks still currently exist (or at least some of them do), and there could be an access problem as even with the little bit of artifact hunting we did, my guide made several calls (we didn't have any problem, though, probably because he knows just about everybody west of Boise City).
At any rate, I thought it was quite a coincidence hearing this only this week and then seeing your post. I'll attempt to talk to Ron, my contact in that area, and dig a little deeper. If access is available, and your feeling froggy enough, we might be able to put you in the middle of all of that. However, a man needs a big lunch bag and a large jug of water for that Godforsaken piece of the world.
Thanks for the reference, and I'll stay in touch on this one.
docmann
PS: I've included a photo of my friend (guide), and his son. In one of the photos, they are examining remnant stones of a teepee ring, in the other, there descending "Workshop" mesa.