Check out this drone video of the largest lake in the USA's state of Pennsylvania, compliments of contributor lleeyyooww. Lake Wallenpaupack is in the heart of the Pocono Mountains, a chain which covers much of the northeastern part of the Keystone State. The lake offers over 80 km (around 50 mi.) of coastline in one of the major recreational areas of the northeastern USA. The Pocono's are part of the Appalachian Mountains system which parallel's the country's East Coast.