DR ROB,not 100% true
You can carry(rifles) in some national parks if you are horse camping.
some national forest are off limits to firearms.
When I was in Okeechobee nat forest FL the local LEO
told me no rifles unless hunting with license
and you need your ccw to carry pistol,no open carry.
The nat forest to the south of me (near Monterey CA)
has no firearms zones, while the nice rangers from Mendicino
told me open carry at your
campsite is ok
I forgot to ask about trails.
They also told me shooting at targets or plinking is ok as long as I
"follow the safety rules every gunowner knows"
I think every state is different,check with the LEO that patrols the area your camping at