Monuments, Statues, and Interpretive Signs Along the Mullan Road, by David and Sue Eakin, is a 63-page photographic inventory of markers found along the historic route from Walla Walla to Fort Benton. After personally traveling the length of the road, the authors documented 62 official marker sites—18 in Washington, 14 in Idaho, and 30 in Montana. Updated in May 2024, the report includes photographs, route maps, descriptions, street and highway locations, and GPS coordinates, making it an exceptionally useful guide for locating and exploring the monuments, statues, and interpretive signs commemorating the Mullan Road.