Bay Facts
The Bay is full of interesting facts and trivia related to its history, wildlife, geography and more.
Can we do more?
Seventy percent of watershed residents want to do more to help make their local creeks, rivers and lakes healthier.
Learn moreCaptain 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 more2 of 5 major ports
Two of the United States’ five major North Atlantic ports—Baltimore and Hampton Roads—are on the Bay.
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.”
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.
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.
Getting oxygen underwater
Just like those on land, animals in the Chesapeake Bay need oxygen to survive. Oxygen is present underwater in dissolved form, and in order to thrive, animals like blue crabs need dissolved oxygen concentrations of three milligrams per liter.
Learn moreNearly 50 thousand miles of rivers, streams and creeks in one watershed
The Susquehanna River watershed includes nearly 50 thousand miles of rivers, streams and creeks.
Saltiest part of the Bay
Salinity is highest at the mouth of the Chesapeake Bay, where water from the Atlantic Ocean enters.
Chesapeake National Recreation Area
Legislation proposed by Maryland’s Senator Chris Van Hollen and Representative John Sarbanes to incorporate the bay into the nation’s park system.
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.
Three geologic regions
The Chesapeake Bay watershed contains three distinct geologic regions: the Atlantic coastal plain, the Piedmont plateau and the Appalachian province.
4,480 square miles of surface area
The surface area of the Bay and its tidal tributaries is approximately 4,480 square miles.
What is brackish water?
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.
100,000 smaller tributaries
The Chesapeake Bay watershed has 150 major rivers and streams, but contains more than 100,000 smaller tributaries.
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 miles long
The Bay itself is about 200 miles long, stretching from Havre de Grace, Maryland, to Virginia Beach, Virginia.
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.
1,300 access sites
There are more than 1,300 public access sites on the Chesapeake Bay and its tributaries.
Learn moreReplacing 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 more12 miles wide
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.
84 degrees Fahrenheit
Water temperatures in the Bay fluctuate widely throughout the year, reaching as high as 84 degrees in summer.
51 billion gallons
Approximately 51 billion gallons of water flow into the Bay each day from its freshwater tributaries.
Learn more12 species of shark
There are twelve known species of shark that have been sighted in the Chesapeake Bay, with only five considered a common occurrence—smooth dogfish, sand tiger shark, sandbar shark, spiny dogfish, and bull shark.