With the 2011 floods of the Mississippi river there's real concern that the Mississippi might jump its channel at the Old River Control Structure and take a shorter path through the Atchafalaya basin, changing the structure and economy of half of Louisiana. In the Internet discussion an astonishingly beautiful set of maps from 1944 keeps turning up. LSU) for the Army Corps of Engineers. They did a huge amount of research on the history of the river course, tracing 20 "stages" of the river course going back some 2000 years. Accompanying 170 pages of sometimes dry text and tables are these fifteen beautiful maps, a tangle of ropes showing the historical Mississippi. Each colour (or stipple) is a former river path and with some squinting you can work out the specific flow of the river in, say, 1765. The real message is the aggregate of all those historical courses, the unmanageable chaos of river meanders.
The report and maps are available for download from the Army but the files are big and pretty unwieldy. I've resized the rectified TIFFs to 25% and uploaded them to Flickr: you can browse them in this Flickr set. The one single image I recommend is Plate 22 Sheet 13: it shows the adjacency of the Mississippi and the Atchafalaya, connected by the Old River where the current water control system is threatened. For a different perspective, check out all the maps assembled into one long picture. It'd be neat to see a zoomable version of this to full resolution.
Update: why yes, it would be neat to have a zoomable version. Try it!