The riding trails aren’t near the gravel pit, you’re missing the point. The point was an example of good stewardship by the users of those areas, to keep them nice.
I obviously like to shoot. We don’t have the right to treat public lands as a garbage dump.
You’re right. These public lands will be easier to keep available if we (the shooting public) would take better care of the sites: Organize an annual clean-up weekend... encourage users to pack out what they pack in... encourage good habits (no glass, no dumping)... things like that.