I see - after reading some responses I've been checking on the NRA website to determine if my state laws supersede federal law or what. Haven't been able to find that info yet.
When I got a CC permit they gave us a list of where we couldn't carry and IIRC it said National Forests. Will find paper and get back to the thread if it's relevant.
I'm sure you're thinking of National Parks.
National Froests are a much different thing, are usually working timber country that is managed and logged, and hunting, recreational target shooting, and being armed while camping and hiking is allowed.
A few months back, Guns and Ammo magazine carried a pretty good overall assessment of weapons laws for various states and Federal holdings. I' dnot recall specifically which issue, but you may want to research a few months back in their RKBA column.
If you hike up any of the National Forest trails here in the High Sierra of California where I live, the Forest Service sign posts warn that if you carry a firearm it is to be used only in an emergency or during legal hunting season. It is only when you reach, say, the the crest of a trail in the wilderness and enter a National Park that you see signs saying "No firearms allowed."
It is legal in California to carry a holstered, loaded, handgun while you are camping on Forest Service (Federal) land.