Yeah, lots of honeypots. Found an insane amount of C. fragilis, a handful of M. navajo, M. mexicanus, three "purplebacks" (undescribed honeypots), P. rugosus, and tiny bleh stuff like Boringmyrmex and Pheidole.
Those "purple-backs" aren't undescribed, they are just unidentifiable until they get workers. There are two or three, and possibly more different species with queens that color. The one's you found are most likely the ones I keyed out to M. mimicus a while back.
Interestingly, I found a whole bunch of them up in Big Bear on my way home from the desert yesterday. I'll be curious to see if these are M. mimicus too. I highly doubt they are M. wheeleri (the other species with queens that color). I actually saw quite a few very active Myrmecocystus nests in both locations that looked like M. mimicus.