Blackscreek road was/is not private land(outside of fenced areas). It was closed down/fenced off by BLM because of shooters leaving garbage out there. TV's, computers, refrigerators, washers/dryers, paper targets, boxes, spent shot gun shells, ammo boxes, etc. were left by people who didn't want them and decided they would take it out to the desert, shoot it up and leave it.
They put up numerous notices warning people they would close it off if it became a problem. Over a year or 2 it got worse, so they fenced it off.
If you head south of kuna mora on pleasant valley road, there's plenty of room. We usually head 10-15 miles south of kuna mora. Be aware that the birds of prey area is near there and that the national guard does maneuvering out there.
Just make sure you pick up your trash. I always come home with more stuff than I brought in. Clean up your area or we will all lose out.