Bay Facts

The Bay’s width ranges from four miles near Aberdeen, Maryland, to 30 miles near cape Charles, Virginia.

The Chesapeake Bay’s land-to-water ratio is 14:1: the largest of any coastal water body in the world. This is why our actions on land have such a big impact on the Bay’s health.

Legislation proposed by Maryland’s Senator Chris Van Hollen and Representative John Sarbanes to incorporate the bay into the nation’s park system.

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.

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

A few deep troughs run along much of the Bay’s length and are believed to be remnants of the ancient Susquehanna River.

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.

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.

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.

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

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.

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

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.

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.”

Salinity is highest at the mouth of the Chesapeake Bay, where water from the Atlantic Ocean enters.

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

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

The Bay and its tidal tributaries have 11,684 miles of shoreline—more than the entire U.S. west coast.

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