The following excerpt is from the 1869 book "Report of the South Pennsylvania Railroad". The book proposes a route for the South Pennsylvania Railroad that would cross Somerset County, Pennsylvania and generally follow the "Old Powder Mill road". The book indicates that the antecedent to the "Old Powder Mill road" was Forbes' French and Indian War road. That is incorrect. Forbes' road was much farther north, and ran between Fort Bedford and Fort Ligonier.
As described in my biography of the gunsmith Elias Knupp, the now abandoned Laurel Hill Tunnel of the Pennsylvania Turnpike was started in the 1800s as a tunnel for the South Pennsylvania Railroad. The western entrance to the tunnel is near Powder Mill Run, and the old Powder Mill Road followed the valley of Powder Mill Run. A short section of Powder Mill Road still survives today, in 2023.
