When shooting in a National Forest, the rules are :
1.) The area must not be closed by order to shooting : call your local Ranger District office and inquire. They will tell you where you can safely shoot and what the regulations are.
2.) Do not shoot from or across any road or trail.
3.) Do not shoot at or across water surfaces, whether creek or lake.
4.) Do not use tracer ammunition.
5.) Do not shoot in or near developed campgrounds or occupied areas.
6.) Do not shoot in an unsafe manner. (that covers a lot of concerns, backstop, other people, drinking, etc.)
7.) Pick up your brass, and every bit of your targets, and take it home with you.
8.) Don't shoot at the trees.
9.) Obey the state and local laws, such as transporting unloaded or in cases, if applicable.