Pennsylvania Turnpike, one of the earliest major limited-access express highways in the United States, opened in 1940 as a state-run toll road running through the Allegheny Mountains and connecting Harrisburg in the east to Pittsburgh in the west. The highway was later extended 100 miles (160 km) east to Philadelphia and the Delaware River and 67 miles (107 km) west to the Ohio state line, making it 359 miles (574 km) long. The turnpike is now paralleled to the north by Interstate 80, a federal highway known in Pennsylvania as the Keystone Shortway.