This interactive map appears on the NOVA site, "Mystery of the Megaflood," about the Ice Age Floods. See the interactive map here. Also see the NOVA home page for the megaflood project (which resulted in a documentary television program).
What I like about the interactive map is the ease of movement from the map itself to various locations on the map with thoughtful narrative and contemporary photograph. What else could one add? (1) GPS coordinated for the photographs. (2) film clips.