Crum Creek was dammed in 1931 near Pennsylvania Route 252 to fill Springton Lake (also known as Geist Reservoir), an approximately 391-acre (1.58 km 2) drinking water reservoir maintained by Aqua America, the county's largest lake. The waterways are, from west to east: the Brandywine River (forming a portion of the county's western boundary with Chester County), Naaman's Creek, Stoney Creek, Chester Creek, Ridley Creek, Crum Creek, Muckinipates Creek, Darby Creek and Cobbs Creek (forming a portion of the county's eastern boundary with Philadelphia). Waterways in Delaware County generally flow in a southward direction and ultimately drain into the Delaware River. The highest point in Delaware County is 500 feet at two points southeast of Wyola in Newtown Township. The lowest point in the state of Pennsylvania is located on the Delaware River in Marcus Hook in Delaware County, where it flows out of Pennsylvania and into Delaware. It is the third-smallest county in Pennsylvania by area.ĭelaware County is roughly diamond- or kite-shaped, with the four sides formed by the Chester County boundary to the northwest, the boundary with the state of Delaware, a portion of the ' Twelve-Mile Circle') to the southwest, the Delaware River, forming the border with the state of New Jersey) to the southeast, and the city of Philadelphia and Montgomery County to the east and northeast. Census Bureau, the county has a total area of 191 square miles (490 km 2), of which 184 square miles (480 km 2) is land and 6.8 square miles (18 km 2) (3.5%) is water. Geography Bartram's Covered Bridge, built 1860 west of Newtown Square, crosses Crum Creek into Chester County Newlin Mill, built 1704, on the west branch of Chester Creek, near ConcordvilleĪccording to the U.S. In 1789, the southeastern portion of Chester County was divided from the rest and named Delaware County for the Delaware River. The riverfront land south of Philadelphia, being the most accessible, was quickly granted and settled. Penn divided his colony into three counties: Bucks, Philadelphia, and Chester. Once the Dutch were defeated and the extent of New York was determined, King Charles II of England made his grant to William Penn to found the colony which came to be named Pennsylvania.

Its original human inhabitants were the Lenape tribe of American Indians.

The land was explored by Henry Hudson in 1609, and over the next several decades it was variously claimed and settled by the Swedes, the Dutch, and the English. History Map of the early settlements of Delaware County, Pennsylvania The old Chester Courthouse, built in 1724ĭelaware County lies in the river and bay drainage area named 'Delaware' in honor of Thomas West, 3rd Baron De La Warr, Governor of the nearby English colony of Virginia. It also is adjacent to the city-county of Philadelphia County and is included in the Philadelphia– Camden– Wilmington, PA– NJ– DE– MD metropolitan statistical area known as the Delaware Valley. The county was created on September 26, 1789, from part of Chester County and named for the Delaware River.ĭelaware County is part of the Delaware Valley and borders Philadelphia, the nation's sixth-most populous city, to its northeast. With a population of 576,830 as of the 2020 census, it is the fifth-most populous county in Pennsylvania and the third-smallest in area. Interactive map of Delaware County, Pennsylvaniaĭelaware County, colloquially referred to as Delco, is a county in the Commonwealth of Pennsylvania.

Delco online