Bay Facts

The 110-mile-long Patuxent River is the longest river to flow exclusively within the borders of Maryland.

While one-third of watershed residents have volunteered their time or donated their money to a charitable organization, less than two in ten volunteers have done so for an environmental organization.

The Chesapeake Bay watershed has 150 major rivers and streams, but contains more than 100,000 smaller tributaries.

Water temperatures in the Bay fluctuate widely throughout the year, reaching as high as 84 degrees in summer.

There are nearly 1,800 local governments in the Bay watershed, including towns, cities, counties and townships.

The Chesapeake Bay holds more than 18 trillion gallons of water.

Forty-six percent of watershed residents never use toxic pesticides in or around their homes. You can evaluate a pesticide’s toxicity to judge the risk in using it, or make your own non-toxic pesticide with garlic, vinegar, cooking oil and other common household items.

Mallows Bay is the final resting place for more than 200 historic shipwrecks dating back to the Revolutionary War. Commonly referred to as the “Ghost Fleet” of Mallows Bay, it is the largest collection of shipwrecks in the Western Hemisphere.

Collectively, the Chesapeake’s three largest rivers—the Susquehanna, Potomac and James Rivers—provide more than 80% of the fresh water to the Bay.

A few deep troughs run along much of the Bay’s length and are believed to be remnants of the ancient Susquehanna River.

The Chesapeake Bay’s land-to-water ratio is 14:1: the largest of any coastal water body in the world. This is why our actions on land have such a big impact on the Bay’s health.

The area of the watershed is about 64,000 square miles.

The Bay itself is about 200 miles long, stretching from Havre de Grace, Maryland, to Virginia Beach, Virginia.

The Bay is surprisingly shallow. Its average depth, including all tidal tributaries, is about 21 feet. A person who is six feet tall could wade through more than 700,000 acres of the Bay and never get his or her hat wet.

In 1524, Italian Captain Giovanni da Verrazano became the first recorded European to enter the Chesapeake Bay.

Major rivers emptying into the Bay include the James, York, Rappahannock, Potomac, Patuxent, Patapsco and Susquehanna from the west and the Pocomoke, Wicomico, Nanticoke, Choptank and Chester from the east.

Legislation proposed by Maryland’s Senator Chris Van Hollen and Representative John Sarbanes to incorporate the bay into the nation’s park system.