Bay Facts

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

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.

The formation of the Chesapeake Bay happened 35.5 million years ago when a meteor collided with Earth, forming a massive crater.

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

Mallows Bay is the final resting place for more than 200 historic shipwrecks dating back to the Revolutionary War. Commonly referred to as the “Ghost Fleet” of Mallows Bay, it is the largest collection of shipwrecks in the Western Hemisphere.

More than 1,800 vessels have met their end in Bay waters, lying broken and battered on the Bay's floor.

There are nearly 1,800 local governments in the Bay watershed, including towns, cities, counties and townships.

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.

There are 6,282,718 acres of accessible green space within the Chesapeake Bay watershed.

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.

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.

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

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

There were many different tribes in the region before Europeans arrived, but the dominant group were Algonquian speakers known collectively as the Powhatan tribes.

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

The Chesapeake Bay is home to 26 different species of submersed aquatic vegetation (SAV), including freshwater plants, estuarine plants, redhead grass, and marine species.