. . . . "Lewis and Clark : the maps of exploration, 1507-1814 / written by Guy Meriwether Benson with William R. Irwin and Heather Moore Riser ; with a foreword by John Logan Allen ; University of Virginia Library / Charlottesville, Va. : Howell Press , cop. 2002" . . . . "4"^^ . . . "2002"^^ . . .