At the end, I see a more modern structure, which I am guessing might be connected with use by Amtrak? Was there a railroad depot/train order office also originally nearby to that site?
The SWP's line you called the Sheepskin was formerly the B&O's FM&P Subdivision (Fairmont, Morgantown and Pittsburgh). With West Virginia University being located in Morgantown and diplomas, in days gone by, were printed on real parchment made from sheepskins - thus the FM&P's nickname became the Sheepskin Line.