Lehigh County: Lehigh County is a county located in the Lehigh Valley region of the U.S. state of Pennsylvania. As of the 2020 census, the population was 374,557. Its county seat is Allentown, the state's third-largest city behind Philadelphia and Pittsburgh. The county, which was first settled around 1730, was formed in 1812 with the division of Northampton County into two counties. It is named after the Lehigh River, whose name is derived from the Delaware Indian term Lechauweki or Lechauwekink, meaning "where there are forks". Lehigh County is included in the Allentown-Bethlehem-Easton, PA-NJ Metropolitan Statistical Area, which is also included in the New York City-Newark, New Jersey, NY-NJ-CT-PA Combined Statistical Area. It is one of the fastest-growing counties in Pennsylvania. The county is named for the Lehigh River, a 109-mile-long (175 km) tributary of the Delaware River, which flows through Lehigh County. The Lehigh River served a vital role in the county's development by offering a transportation and trading route for its mining products, including iron, manganese, limestone, and ultimately manufactured steel products. |