I'm just guessing here, but perhaps the person was talking about the FEMWIN events that are held once in a while in Vegas. Go to FEMWIN.com and check out the VIP Event coming this April 24, 25 and 26. It is not the first event of this kind that FEMWIN has held in Vegas. I would consider that event as "underground" because of the limited exposure and audience. It is certainly not mainstream.
I copied the link here if it helps:
http://femwin.com/eventLasVegasApril2015.htmCindy Huntress is supposed to be at this year's event. Geez, come to think of it, I should move to Vegas.
I'm also aware of some women who have flown to Vegas (with their lucky hubbies) for a private event in which they wrestled each other during a weekend. Some of these women do travel to different locations for their events, and Vegas is a popular place to meet. I've also heard of Niagara Falls as a meeting place for private wrestling events as well. I have seen pics of these private events from another source.
That being said, there may well be an underground fight club in Vegas. I just wanted to add my two cents worth to the discussion...
Cheers,
Wrstlvr.