I like SASCO, it's owned and operated as an actual airsoft field, so the legalities are cleared up, I sent the owner an email, but never got a reply, I'll try a phone call today and let you guys know how it goes.
EDIT
I was thinking of another location, SASCO is BLM land, but still our best bet! SASCO OR BUST
Yes, it is a one day Op. We're going to have a carpool set up from Phoenix, we'll most likely meet in a Parking Lot in South Phoenix, all load up into the designated cars, then drive down. Anyone who wants to drive is encouraged to stop by the carpool area and take some of the people in their vehichle, and people are encouraged to give a few dollars to the driver to cover a portion of the gas. It's not required, but it's a nice gesture.