Bay Facts
The Bay is full of interesting facts and trivia related to its history, wildlife, geography and more.
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.
Saltiest part of the Bay
Salinity is highest at the mouth of the Chesapeake Bay, where water from the Atlantic Ocean enters.
87 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.
The Chesapeake Bay's first inhabitants
The first inhabitants of the Chesapeake Bay region are referred to as Paleo-Indians. They came more than 10,000 years ago from other parts of North America, drawn in by the abundance of wildlife and waterways.
Learn more100,000 smaller tributaries
The Chesapeake Bay watershed has 150 major rivers and streams, but contains more than 100,000 smaller tributaries.
12 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.
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 moreFirst recorded European to enter the Bay
In 1524, Italian Captain Giovanni da Verrazano became the first recorded European to enter the Chesapeake Bay.
Longest river fully within Maryland
The 110-mile-long Patuxent River is the longest river to flow exclusively within the borders of Maryland.
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.
First estuary targeted for restoration
The Chesapeake Bay was the first estuary in the nation to be targeted for restoration as an integrated watershed and ecosystem.
Learn moreWhat 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.
1.6 billion pounds of blue crabs
Since 1990, commercial watermen have harvested more than 1.6 billion pounds of blue crabs from the Bay. Data show commercial harvest has experienced a steady decline, and in 2014 hit the lowest level recorded in 25 years: 35 million pounds.
Learn more4,480 square miles of surface area
The surface area of the Bay and its tidal tributaries is approximately 4,480 square miles.
174 feet deep
The deepest part of the Bay, located southeast of Annapolis near Bloody Point, is called “The Hole” and is 174 feet deep.
1,300 public access points
There are more than 1,300 public access points on the Chesapeake Bay and its tributaries.
Learn moreChesapeake 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.
4,863 feet above sea level
At 4,863 feet above sea level, Spruce Knob is the highest point in the Chesapeake watershed.
Where does the Bay get its water?
The Bay receives about half its water volume from the Atlantic Ocean in the form of saltwater. The other half (freshwater) drains into the Bay from the enormous 64,000-square-mile watershed.
Filtering drinking water
Forests and trees help filter and protect the drinking water of 75% of watershed residents.
Learn more18 trillion gallons
The Chesapeake Bay holds more than 18 trillion gallons of water.
Remnants of an ancient river
A few deep troughs run along much of the Bay’s length and are believed to be remnants of the ancient Susquehanna River.
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.
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.
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