Go south of the airport, past the jails... once south of the massive powerlines you're legal to shoot (prior to that you're mostly in the "Bird of Prey" reserve... can't shoot there apparently)
before the power lines used to be open for shooting. The area got trashed and the shooters got moved further out in the desert. Most places close to residential areas are getting closed and solely due to the noise. Last summer there was a proposal to close off a huge area of the desert due to all of us supposedly being a bunch of trashy, drunken, atv-riding tank shooters. Judging from the trash out there the last time I went, I'm sure we'll have to go further out in the desert soon.
Assholes not cleaning up after themselves is what got Blacks Creek closed down. And yeah, it was shooters to (a large part of it was shooters).
There's no shortage of brass and shotgun shells under the power lines either, as well as the remains of targets people haul out there and leave behind.