A local area has gone to great lengths to put up signage stating that unlicensed off-highway vehicles are NOT ALLOWED to travel the main stretch of USFS fire road. So what are people doing? Screaming up and down that very road on unlicensed off-highway vehicles at 2/3x the posted speed limit. Shooting is supposed to be confined to specific areas with backstops - instead you've got dingbats firing off hundreds of rounds into valleys with NO BACKSTOP and they aren't even cleaning up their brass.
It's a goddamn shit show.
BLM and USFS websites have horrible navigation. Just Google the name of the forest with "MVUM". You might also need to first Google forest name + district map and then Google MVUMs for the specific district.
Another option is the MVUM layer in CalTopo (the name comes from the fact it started as just CA, but it's national nowadays)
[0] https://www.otherhand.org/home-page/search-and-rescue/the-hu...
Even as late as the last couple of winters, idiots follow GPS guidance (Waze, google/Apple Maps) onto closed roads. Again, know your environment. If a major highway is closed, likely the minor side roads are as well.