Map of Beaver County showing outcrops of the Pittsburgh, Upper Freeport and Kittanning coals / Second Geological Survey of Pennsylvania ; J.P. Lesley, state geologist ; I.C. White, ass't. geologist, 1876.
From Parts (In 6 layers) Depicts: 1877 Last modified almost 3 years ago. 5 control points.
A low resolution preview is shown below.