The Commonwealth of Pennsylvania took aerial imagery of the slate belt during the years of 1938 and 1939, a moment at the end of the slate industry's most prosperous years beginning in the 1880's and ending at the start of the Second World War. These images provide clear evidence of the location of quarries many still active at the time. All were used to identify the actual location of more than 350 individual quarries stretching across the district, each described in Charles Behre's book "Slate of Pennsylvania" written in 1933.
These images, which were downloaded from Penn Pilot, were geolocated using Google Earth which allows them to appear in their proper location within the software. Each of those geolocated high resolution images can be downloaded and then viewed in Google Earth by clicking on the links to the left.
Below are a few examples of the difference between the landscape of today and the same landscape as it existed in 1938. By moving the slider bar you can see thow much the landscape has changed. A full set of these images are available to download and are viewable in Google Earth. To open the page for downloading CLICK HERE.