Delaware River

A 2012 view of the Delaware River near the place where George Washington's troops crossed the ice-laden river on Christmas night of 1776, perhaps 100 miles upstream (north) of the point where the river broadens to become the Delaware Bay.

A map of the Delaware River watershed which reaches into four U.S. states.

The Delaware River's headwaters are in New York state and northern Pennsylvania. It is a popular area for watching bald eagles in wintertime.

At 282 miles long, the Delaware River is the longest free-flowing (undammed) river in the eastern United States. It is a state dividing line, with Pennsylvania's east side (and a bit of Delaware) on its western shore. On its eastern shore is a bit of southwest New York, and then all of New Jersey's west side.

The Delaware River provides drinking water to over 17 million people. Its watershed reaches into four states: New York, Pennsylvania, New Jersey and Delaware. In 1988, the non-profit Delaware Riverkeeper Network was created to address issues of habitat pollution and restoration across the entire watershed, and to advocate for clear water policies nationwide.

On March 24, 2023, there was a serious spillage of acrylic latex polymer into Otter Creek, leading to the Delaware River. The spill was from the Trinseo Altuglas facility in Bristol, PA, and released about 8100 gallons of the pollutant into the creek, and possibly as much as 12,000 gallons. The spill potentially impacted four drinking water systems on both the Pennsylvania and New Jersey sides of the river, as well as the natural environments attached to the river, Otter Creek, Mill Creek, and the Bristol Marsh.

A lot more information about the Delaware River and its watershed is in Wikipedia's Delaware River article.