I use similar analyses of overhead imagery to re-discover "vanished" early (1810's -- 1840's) "roads, trails and traces" here in northeastern Texas. In the course of GPS-mapping old roads, for my (in-process)
"Atlas of Early Northeast Texas", I have also re-discovered several "lost" settlements and the remains of a very old bridge -- 'way out in the middle of the woods.
Here in timber country, sometimes the only clues are slight changes in the way the timber grows on old, disturbed soil... Infrared images are particularly helpful in that respect.