Bay Facts

Water temperatures in the Bay fluctuate widely throughout the year, dropping as low as 34 degrees in winter.

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

The Bay’s width ranges from four miles near Aberdeen, Maryland, to 30 miles near cape Charles, Virginia.

The 195-mile-long Rappahannock River is the longest free flowing river in the Chesapeake Bay watershed.

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

During the winter, the Bay supports 87 species of waterbirds. Of these wintering waterbirds, 14 species rely on the Bay to serve as habitat for more than 10% of their continental populations.

The Chesapeake Bay watershed stretches approximately 524 miles from Cooperstown, New York, to Norfolk, Virginia. It includes parts of six states—Delaware, Maryland, New York, Pennsylvania, Virginia and West Virginia—and the entire District of Columbia.

Two of the United States’ five major North Atlantic ports—Baltimore and Hampton Roads—are on the Bay.

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

Most of the water in the Bay, including in the middle portion of the Bay and its tidal rivers, is brackish–a mixture of salty and fresh, with a salinity level of greater than 0.5 ppt but less than 25 ppt.

The mouth of the Chesapeake Bay is about 12 miles wide between its northern point near Cape Charles, Virginia, and its southern point close to Cape Henry, Virginia.

Nine in ten watershed residents never toss food wrappers, cups or cigarette butts on the ground. Almost eight in ten watershed residents pick up litter when they see it.

There have been 10 U.S. presidents from the Chesapeake Bay watershed, including George Washington, Thomas Jefferson, James Madison, James Monroe, William Henry Harrison, John Tyler, Zachary Taylor, Woodrow Wilson, James Buchanan and Joe Biden.

Half of pet owners always pick up after their pet, but one-third of pet owners seldom or never do so. Pet waste contains bacteria that can harm human health and contaminate the water we use for drinking, swimming and fishing.

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.

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

The Susquehanna River is the Bay’s largest tributary, and contributes about half of the Bay’s freshwater (about 19 million gallons per minute).