Pennsylvania State Route 642 is an east-west highway across Northern Union County. It runs from the Northumberland/Union County Line, at Milton, to U.S. Rt. 15, at West Milton. PA St Rt 642 passes through the following towns in Union County. West Milton PA St Rt 642 is not multi-plexed in Union County. PA St Rt 642 intersects the following highway in Union County. U.S. Rt. 15, at West Milton.
WB PA St Rt 642 at the Northumberland/Union County Line. The western end of PA St Rt 642. The western end marker.
