Yes, these are all backcountry areas. If you’re staying in a place with reservations none of this applies, but most parks around here just have tenting, no shelters.
In the Whites, Greens, and Daks all backcountry shelters are first come first served.
Unless things have changed, in a national forest you can camp anywhere as long as there are no restrictions on camping in that area of the forest.
Many national forests have restrictions that apply to large chunks of the land. The White Mountain National Forest (in NH and ME) has 5 wilderness areas, above treeline rules, special restrictions on two major river drainages, and no camping zones 1/4 mile around all shelters, backcountry campsites, huts, and roads. The suggested rule in all the rest of the NF is 200’ from trails or water sources. These cover lots of the most popular hiking areas.
My regular pack for a day hike runs around 20 pounds. That includes almost entirely emergency medical kit, associated supplies, snacks and water.
My extended pack runs about 60 pounds, and the first session of the season always, always, always sucks. Subsequent ones are much easier, as my body remembers how to do this.
60 pounds is just under a third of my weight; so that makes perfect sense to me.
From what I know the national forests in NC don’t have a lot of off limits camping areas but my knowledge is 15 years old. We don’t have areas above the treeline here. Most people camp in the campgrounds anyway rather than out in other areas of the forests.
Seconded. On a recent ten-day climbing trip in Denali, I had a 72-pound pack and a 50-pound sled, plus probably another few pounds of tools and whatnot around my waist. Winter requires more food, 4-season tents, extra sleeping pads, extra fuel, extra clothes and other stuff (ice protection, anchors, axes, etc.) that weighs you down.
In the summer, I can pretty easily limit a weeklong load to under 50 pounds, but not much under at the outset if I want to eat well.