Harveys Lake, a natural glacial lake in northeastern Pennsylvania, is the state’s largest natural lake by volume and second largest by surface area. Discovered in 1781 by Benjamin Harvey and settled in the 1790s and early 1800s, it supported farming and major lumbering before becoming a popular summer resort by the late 1800s and early 1900s, aided by rail service, hotels, steamboat excursions, and amusements. The lake later served as a water and ice source, but nutrient pollution damaged water quality and led to recurring algae blooms. Restoration efforts have reduced phosphorus, and the lake remains a heavily used recreation area as well as an important natural site.