See the Mississippi River's hidden history, uncovered by lasers

National Geographic 

For cartographers and cartophiles, Harold Fisk's 1944 maps of the lower Mississippi River are a seminal work. The centerpiece of his report was 15 maps showing the meandering Mississippi and its historical floodplains stretching from Missouri to southern Louisiana. More than seven decades later, Daniel Coe, a cartographer for the Washington Geological Survey, wanted to re-create Fisk's maps with greater accuracy and a new aesthetic. Coe had the advantage of hyperprecise U.S. Geological Survey (USGS) data collected using lidar, a system of laser pulses sent from aircraft to measure topography. The lasers detect the river's shape along with everything around it--every house, tree, and road.