However, some of the infrastructure is old, like the 100-year-old, 19-mile-long Mountain Tunnel, which is a key conduit for the Hetch Hetchy water flow on its route to the Bay Area. But a project ...

The area of the Allegheny Mountain Tunnel along the Pennsylvania Turnpike would instead be a 1,000-foot-wide gash in the mountain if plans by the Pennsylvania Turnpike Commission follow through.