Bay Facts

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

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.

More than 1,800 vessels have met their end in Bay waters, lying broken and battered on the Bay's floor.

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.

The surface area of the Bay and its tidal tributaries is approximately 4,480 square miles.

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.

There were many different tribes in the region before Europeans arrived, but the dominant group were Algonquian speakers known collectively as the Powhatan tribes.

The Chesapeake Bay watershed contains three distinct geologic regions: the Atlantic coastal plain, the Piedmont plateau and the Appalachian province.

The Chesapeake Bay was formed about 10,000 years ago when glaciers melted and flooded the Susquehanna River valley.

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.

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.

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

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

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

There are as many as 200 invasive species present in the Chesapeake Bay watershed that are causing some serious issues in an already-stressed ecosystem. Some examples include blue catfish, snakehead, zebra mussel, purple loosestrife, and nutria.

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

Captain John Smith and his men sailed the Chesapeake Bay in a modest wooden boat called a shallop–an open wooden workboat such as a barge, dory, or rowboat that was small enough to row but also had one or two sails.