I went out there once (didn't shoot) to check the area out.
There are no trespassing signs posted (they have been shot at) There's some PG&E equipment (natural gas?) out there, The place has also been treaded like a dump, with a lot of garbage. Like others have said, the water area and beyond (the place you would shoot into) is a protected wetland.
It's not worth the risk. I've heard stories of the Yolo sheriff showing up out there as well.
Just go to YSA, it's a few miles away. Yes, you have to follow range rules and pay a few bucks, but it's a lot better than loosing your guns and your rights.