The Breaking of Northwall
Part of a series of 7 books about a series of adventures in long walks or travels by "loners"  in the post-apocalyptic United States.  Blends fighting adventures with philosophic travels of villagers and outsiders.  Be patient, the books are quite different, but build in a slow intelligent blend to a very meaningful final book.
Visionaries, Exiles, Nuclear warfare, Regression (Civilization), Tribes
Paul O. Williams