1. Mississippi River. Alluvial valley of Mississippi River, index map of quadrangles, reduced from basin maps. Scale 10 m.=1.3 in., scale 1:500,000. Edition 1939. Army Map Service, Army, Washington, D. C., 1943 [printed for Mississippi River Commission, Aug. 1946]. Bookmark Corporate/Agency Authors: Mississippi River Commission and War Department Publisher: Mississippi River Commission Date: [January 1947] SuDoc number: W 31.9/2:946/sh.1,2