it's sort of similar in a way, i mean in that there are public records you can check for maps and who owns a piece of land, etc.
other than that use common sense: can you set up a trail that won't be obvious to most people? depending on the area you could use a foot, deer or mountain bike trail, or whatever. you could have a trail starting straight off a motor road. but in any case you want to think about who is going along that path and how fast and what they will notice - maybe you can have your squat-trailhead start behind a tree, a conveniently flexible bush branch, or whatever.
then the squat itself you want to place either in a location no one will have much of a chance of seeing, or you want to make sure it's covered in green and/or brown tarps. or if its sturdy enough/you dont want to stay that long you could even just pile up branches and brush all over it.
didnt you live in santa cruz for years? why didn't you ask the woodsies? hipster asshole.