Pennsylvania State Route 642 is an east-west highway across Southern Montour County. It runs from the Northumberland/Montour County Line, near Potts Grove, to the Montour/Columbia County Line, near Jerseytown. PA St Rt 642 passes though the following towns in Montour County. Mooresburg Mausdale PA St Rt 642 is multi-plexed in Montour County. Pennsylvania State Route 54, at Mausdale. PA St Rt 642 crosses the following highways in Montour County. Pennsylvania State Route 45, near Mooresburg. Pennsylvania State Route 54, at Mausdale. Pennsylvania State Route 54, at Mausdale.
