Once you are all set up, go inside and check in with Security at the door. You are totally fine to 'make camp' here, set out the BBQ and chairs, just don't take up tons of space or block anyone in. When you pull in, to your left is a dirt lot (not level) that you are allowed to park in.
Easy access on your way in or out to fuel at the Pilot off the 99. This is a great spot, I am becoming a regular here because its quick off the 99 near madera, every time I come through I stop in.
