This is part of an old train line that went through Genesee County at one time. I found this old bridge support on Old Creek Road last year and then, over the winter, while playing around on Genesee County's GIS map, I found an old right-of-way in Le Roy that is still owned by Lehigh Valley Railroad (even though Lehigh went bankrupt in the 1950s).
I traced the one parcel I found owned by Lehigh. At one time, it went through most of the county (The right-of-ways are still all separate parcels for the most part, owned by many different people.) The railroad left a permanent scar visible from the satellite images, so it's easy to trace. The line I found passed through this section of Old Creek Road in Alexander.
UPDATE: A caller says that this railroad location was part of the Delaware-Lackawana line, which merged with the Erie Line in 1961. The merger meant this railroad line was taken out of commission. The Lehigh line, he said, is further to the north.
