Where are you located? That will go a long ways in helping us give you suggestions. I just returned from a gun show and the BLM (Bureau of Land Management) was there with maps showing where it was legal to shoot in Utah. One fellow there in front of me was complaining that the sheriff of Tooele county had told him there was NO PLACE in Tooele county he could shoot. The BLM lady laughed and said, "he only wishes" and proceeded to show the guy that he could go out on BLM land (they own most of Utah) and except for a few restricted areas he could shoot his to his hearts delight. So don't automatically assume your local LEO will level with you. The sheriff was lying to fit his agenda.
They provided me with maps showing where one could go and shoot with a few restrictions, which basically meant pick up after yourself, don't shoot stuff you can't cleanup afterwards.
If you live out west most of the land is federal land and you can check with them for maps of restricted areas.