If the map you are talking about is the one linked in this paper, the area of interest would be the one near Douglas, AZ, in the area of points numbered 14 and 20 on page 6.

https://repository.arizona.edu/handle/10150/629471

However, this map is dated as being from 2001, and it is not the map I recall. The map I recall showed two oil fields of long, slender shape, with the larger portions of each being in Mexico. Compared to the 2001 map, the feature shown at or near Douglas extends further north and deeper into Cochise County.

The two fields shown on the map I recall include portions in Mexico. They are parallel, and both trend SSE by NNW. Moreover, no other fields or potential fields were shown, as the map's point was to include major undeveloped fields extending from Mexico into the US (Arizona and New Mexico only).

Oddly enough, the "Bisbee Formation" you reference is not in Chosise County.

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"...could those licensed entities BE market makers who are obligated to buy and sell to create activity even if just small numbers?"

I don't know, but I doubt it because market makers should not also be playing the role of market disruptors.