This print forms part of the Geological survey of the alluvial valley of the lower Mississippi River, a report commissioned from the geologist Harold Fisk by the US Army Corps of Engineers and published in 1944. This map is the sixth of the fifteen that make up the series, and covers the route from Tunica (Mississippi) to Phillips County (Arkansas).

The aim of the report was to determine the nature and origin of the Lower Mississippi alluvial valley; to this end, Fisk reconstructed its geological evolution up to the year 1944. To this end, he carried out more than 16,000 subsoil soundings, which enabled him to gather data on the river’s former courses. Fisk and his team supplemented this information with three historical maps and a series of aerial photographs to gain a better understanding of the area.

The result is a map that superimposes, within the same geographical area, the river’s historical course over time – shown in different colours – and its current course, shown in white. The belt of meanders visible on this map, with its intertwined loops and abandoned channels, reflects the lateral spread of the river over millennia in this central section of the alluvial valley.

You can read more about Fisk’s cartographic method and the history of these maps in the newsletter article Harold Fisk and the meanders of the Mississippi.

Sources

• The Alluvial Valley of the Lower Mississippi River – Radical Cartography