The Panama Canal Historical Atlas by William R. Shepherd, 1911 (380K)
The Canal Zone. Profile of the Canal.
The following three maps are from "Operation Just Cause: The Incursion Into Panama", U.S. Center of Military History, 2004.
1:250,000 - Latin America (aeronautical charts) Joint Operations Graphic, U.S. National Imagery and Mapping Agency (dates vary) Not for navigational use