This stretch of the abandoned turnpike is 13 miles long, and was abandoned in 1968. It includes two tunnels, Rays Hill and Sideling Hill. I had hoped to bike the whole segment, but rain set in, and the trip had to be cut short.
So, the trip only included a ride through the Sideling Hill Tunnel, 1.3 miles of inky darkness.
This section of the Turnpike opened in 1940, and was bypassed in 1968 because it was cheaper than twinning the two tunnels. It's an eerie site. It's out in the middle of nowhere, and seems some remnant of a post-apocalyptic world. The whole time we spent on the old turnpike, we saw only two other people, local teens by the look, emerging from the darkness on foot.
The tunnels actually date back to 1881 and the construction of the South Penn Railroad, which went bust before completion. In the late 1930s, the Pennsylvania Turnpike Commission completed and expanded the tunnels.
However, most of the railroad line follows a different alignment from the Turnpike. In places, you can see traces. Several photos in my set show the railroad grade (and a culvert) just west of the western portal of the Sideling Hill Tunnel.