Adding Boone and Dropping Undaunted Courage. Encounters at the Heart of the World: A History of the Mandan People is in progress and is great so far.Daniel Boone: The Life and Legend of an American Pioneer - great story, but dense read. I'd find another Boone biography.
Nine Mile Bridge by Helen Hamlin - a book about a game warden's wife when they lived in the North Maine Woods
That Wild Country by Mark Kenyon - he tries to walk as independent as he can, but makes some completely false and politically charged comments not related to the PL movement.
Undaunted Courage by Stephen Ambrose - fast-moving account of the Lewis and Clark Expedition.