U.S. Fish & Wildlife ServiceThis webmap is derived from an online source (https://www.digitalcommonwealth.org/search/commonwealth:7h14b0450). Map of the alluvial valley of the Mississippi River from the head of St. Francis Basin to the Gulf of Mexico, showing lands subject to overflow, location of levees and trans-alluvial profiles The map shows the landscape configuration and the approximate extent of overbank flooding before extensive construction of the levees in the early 1900s. The map was georectified using ERDAS Imagine and contemporary data sources. Edited (to correct position of panels) and georeferenced by Yvonne Allen (USFWS) to geographic NAD1927 using ArcGIS , 3rd order polynomial and 80 ground control points using lat lon grid. Online repo: https://www.sciencebase.gov/catalog/item/58f66491e4b0bd52222f7821ArcGIS ImageMapLayerhttps://hub.arcgis.com/datasets/6941d5d2a1a84d05b771ef854a192d40engU.S. Fish and Wildlife Service Open DataPublicLower Mississippi River - circa 1899 [United States]Web servicesUnited StatesLast Modified: 2025-04-14