The Delaware River watershed is known for the amazing recreational opportunities at its national parks and public lands, from paddling and hiking throughout the Delaware Water Gap National Recreation Area and its National Wild and Scenic Rivers in Pennsylvania and New Jersey, or learning about our nation’s history at First State National Historical Park in Delaware.

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Delaware River Watershed map: The image is a map showing the Delaware River Watershed that traverses the borders of New York, New Jersey, Pennsylvania, and Delaware. There are 13 national park units within the watershed.

Delaware River Watershed map: The image is a map showing the Delaware River Watershed that traverses the borders of New York, New Jersey, Pennsylvania, and Delaware. There are 13 national park units within the watershed. camera icon ©NPCA

What is a Watershed?

A watershed is an area of land where all forms of precipitation drain into a stream or river, with a portion absorbed into the ground. Watersheds can be large or small land areas of land. Larger watersheds are made of a network of many smaller ones.

The Delaware River Watershed includes four states spanning over 13,539 square miles, flowing from the Catskill Mountains in New York through Pennsylvania, New Jersey, and Delaware before reaching the Delaware Bay. There are over 2,000 streams and rivers within the Delaware River Watershed. The two largest are the Schuylkill and Lehigh Rivers in Pennsylvania. The Delaware River is 330 miles long and is the longest undammed river in the eastern United States.

The Delaware River Basin is also home to a large variety of plants, wildlife, and aquatic life, including more than 400 bird species and more than 100 species of fish, including the American Eel, American Shad, and the Atlantic Sturgeon. The Upper Delaware River Basin is home to a world-class trout fishery and is a popular wintering destination for bald eagles escaping winter conditions from northern areas.

The watershed faces environmental challenges, including pollution and floods, which threaten its delicate ecosystem.

History and Culture

We gratefully acknowledge the Native Peoples on whose ancestral homelands we gather, as well as the diverse and vibrant Native communities who make their home here today.

The Delaware River Watershed is rich in history and culture, spanning thousands of years. The Lenape, “The people” in their language, were the original stewards of the lands within Delaware, Pennsylvania, New York and New Jersey and Ohio. The Lenape established settlements up and down the Delaware and Hudson Rivers, where they farmed, hunted, fished and gathered for food, as well as traded with other Nations. They were some of the first Indigenous people in North America to encounter European explorers and English settlers. The Lenape people were also the first Indigenous peoples to sign treaties with European settlers and later the United States. Even with these peace agreements, the Lenape encountered conflict and forced removal from their homelands by deception and disregarding the treaty agreements. Today, there are several Lenape Nations within Oklahoma, Wisconsin and Ontario.

In the 17th century, European settlers established towns and industries along the riverbanks. The Delaware River played an important role during the American Revolutionary War in 1776 when George Washington crossed the river to lead troops into a winning battle near Trenton, New Jersey. Today, the watershed is home to a growing and diverse population.

The Delaware River Watershed is a reflection of the United States’ diverse population and landscape. The watershed is home to over 8 million people and is the source of drinking water for 14.2 million people, or roughly five percent of the U.S. population. Forests, farmlands, wetlands, grasslands, and a variety of bodies of water cover the watershed. This nature getaway with endless recreational experiences is just a short distance from the New York City and Philadelphia metropolitan areas.

Importance to the Economy

The Delaware River Basin is an economic generator for its surrounding communities. It contributes approximately $25 billion annually in economic activity from trade and commerce, manufacturing, and agriculture, in addition to $21 billion in ecosystem goods and services. It supports an internationally renowned cold water fishery that generates over $21 million in annual revenue through tourism and recreational activities. In 2021, the Delaware Water Gap National Recreation Area generated $235 million for local businesses. To learn more about how the Delaware Water Gap National Recreation Area drives local economies through outdoor recreation, visit our interactive Economic Impact Report.

History of Protection

Over the years, leaders have made efforts to clean and protect the Delaware River Watershed. In 1961, President John F. Kennedy signed an interstate compact between Pennsylvania, Delaware, New York, and New Jersey to establish the Delaware River Basin Commission (DRBC). DRBC unifies the four states’ resources to manage the river together without regard to political boundaries. A decade later, the Clean Water Act of 1972 provided the federal government with authorization and funding to regulate pollution and build infrastructure to remove sewage, trash, oil, and toxic industrial waste from the river.

Visiting National Parks in the Delaware River Watershed

Fact Sheet

FAQ: Delaware Water Gap National Recreation Area and Brandywine Valley at First State National Historic Park

Know Before You Go! Before heading out, learn more about visiting these two national park sites from our Frequently Asked Questions (FAQ).

See more ›

The Delaware River Watershed is home to nine national park units. Explore the beauty and importance of the Delaware River, and discover why it is a vital part of our natural and cultural heritage by visiting national park sites in the watershed:

Appalachian National Scenic Trail
Delaware Water Gap National Recreation Area
Edgar Allan Poe National Historic Site
First State National Historical Park
Hopewell Furnace National Historic Site
Independence National Historical Park
Lower Delaware National Wild and Scenic River
Middle Delaware National Scenic and Recreational River*
Thaddeus Kosciuszko National Memorial
Upper Delaware Scenic and Recreational River
Valley Forge National Historical Park

*The Middle Delaware is a 40-mile stretch within the Delaware Water Gap National Recreation Area


Congress: Aid the Park Service in managing historic and cultural resources.

Urge Congress to support H.R. 7936, Representative Paul Tonko’s legislation to provide $250 million for long-underfunded cultural resources and history programs at America’s national parks. We must ensure America’s national parks and the people who work so hard to protect them are prepared against climate change.

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