Bay Facts

At 4,863 feet above sea level, Spruce Knob is the highest point in the Chesapeake watershed.

Eighty-six percent of watershed residents believe if people work together, water pollution can be fixed.

The widest point of the Chesapeake Bay measures 35 miles, and is located near the mouth of the Potomac River.

In 1524, Italian Captain Giovanni da Verrazano became the first recorded European to enter the Chesapeake 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.

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.

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

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

While one-third of watershed residents have volunteered their time or donated their money to a charitable organization, less than two in ten volunteers have done so for an environmental organization.

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

At filter feeders, oysters can filter up to 50 gallons of water a day.

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

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.”

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

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

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