Here is how I found my shooting spots ( I hate Nazi ranges) Most public land is OK to shoot on, Forest Service, BLM land etc. I know because my father was in the F.S. for forty years in the N.W. Go to any Forest Service ranger station and ask the question "is there somewhere I can shoot around here that is SAFE" they will probably be more than happy to give you a map to the FS roads with spots that are known for this, they are usually gravel pits dug out of hills to put gravel on the mountain roads and are often only known to a few.I have done this with great succes. I always take a large Hefty bag with me and fill it with more garbage than I go in with in hopes of minimizing the damage from others, hoping to keep access open for everyone. The only rules that apply are the basics, of which they will inform you:
No shooting within (some reasonable distance of campgrounds, don't know exactly but it is obvious)
No shooting across roads
No shooting across bodies of water
Etc., Etc. Etc.
Just go out far enough and if someone gives you a hard time tell them the Park Ranger said this is the place to shoot safely.
Hope this is helpful.