Bay Facts
9.6 million acres of land
Approximately 9.6 million acres of land in the Bay watershed have been permanently protected from development by Bay Program partners.
Learn more200 invasive species
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.
Longest free flowing river in the Bay watershed
The 195-mile-long Rappahannock River is the longest free flowing river in the Chesapeake Bay watershed.
Replacing grass lawn with native plants
Twenty-six percent of watershed residents have replaced an area of their grass lawn with native plants. Native plants provide food and habitat to bees, birds and butterflies, and often don’t need to be watered or fertilized.
Learn more3,600 species of plants and animals
The Bay supports more than 3,600 species of plants and animals, including 348 species of finfish, 173 species of shellfish, over 2,700 plant species and more than 16 species of underwater grasses.
Learn more64,000 square miles
The area of the watershed is about 64,000 square miles.
80% of the Bay's freshwater
Collectively, the Chesapeake’s three largest rivers—the Susquehanna, Potomac and James Rivers—provide more than 80% of the fresh water to the Bay.
1,800 local governments
There are nearly 1,800 local governments in the Bay watershed, including towns, cities, counties and townships.
Meaning of "Chesepiooc"
The word Chesepiooc is an Algonquian word referring to a village "at a big river." In 2005, Algonquian historian Blair Rudes helped dispel the widely-held belief that the name meant “great shellfish bay.”
18 trillion gallons
The Chesapeake Bay holds more than 18 trillion gallons of water.
1,800 sunken vessels
More than 1,800 vessels have met their end in Bay waters, lying broken and battered on the Bay's floor.
35.5 million years
The formation of the Chesapeake Bay happened 35.5 million years ago when a meteor collided with Earth, forming a massive crater.
Six states and the District of Columbia
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.
10,000 years old
The Chesapeake Bay was formed about 10,000 years ago when glaciers melted and flooded the Susquehanna River valley.
84 degrees Fahrenheit
Water temperatures in the Bay fluctuate widely throughout the year, reaching as high as 84 degrees in summer.
21 feet deep
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.
Captain John Smith visits the Bay
In 1608, Captain John Smith set off on the first of two voyages where he charted the land and waterways, and later drew an elaborate and remarkably accurate map of the Chesapeake Bay.
Learn moreLargest estuary in the United States
The Chesapeake Bay is an estuary: a body of water where fresh and salt water mix. It is the largest of more than 100 estuaries in the United States and third largest in the world.
Learn more12 major rivers
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.
35 miles wide
The widest point of the Chesapeake Bay measures 35 miles, and is located near the mouth of the Potomac River.
80,000 acres of underwater grasses
Nearly 80,000 acres of underwater grasses grow in the shallows of the Chesapeake Bay and its tributaries. Young and molting blue crabs rely on underwater grass beds for protection from predators.
Learn more11,684 miles of shoreline
The Bay and its tidal tributaries have 11,684 miles of shoreline—more than the entire U.S. west coast.
29 species of waterfowl
The Chesapeake region is home to at least 29 species of waterfowl.
Learn more87 species of waterbirds
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.