Thompson, Todd A.(Todd Alan), 1959-cartographer.Includes illustrations, text, graphs showing "Lake-level fluctuations over the past 4,700 years" and a timeline showing historical events since 1166 B.C. tied to specific beach ridges. "Poster 1.1.""The map below was created by tracing beach ridges from a series of aerial photographs of northern Lake and Porter Counties taken in 1938."Imprint: [Bloomington, Ind.] : Indiana University, Indiana Geological Survey, 2000.Dimensions: 76 x 87 cm; Scale: 1:59,000Coordinates: W0873136 W0871307 N0414539 N0410943JPEG98bd763f-3506-433d-8837-f1a81b0afb45G4093 .L3C2 2000 .T486engIndiana. Geological SurveyPublicLakesBeach ridgesAncient shorelines of Southwestern Lake MichiganMapsIndiana--Porter CountyIndiana--Lake CountyLake MichiganIndiana2000Indiana University