Bay Facts

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

Captain John Smith and his men sailed the Chesapeake Bay in a modest wooden boat called a shallop–an open wooden workboat such as a barge, dory, or rowboat that was small enough to row but also had one or two sails.

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

Nine in ten watershed residents never toss food wrappers, cups or cigarette butts on the ground. Almost eight in ten watershed residents pick up litter when they see it.

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

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

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

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

There are as many as 200 invasive species present in the Chesapeake Bay watershed that are causing some serious issues in an already-stressed ecosystem. Some examples include blue catfish, snakehead, zebra mussel, purple loosestrife, and nutria.

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.

The narrowest point of the Chesapeake Bay measures 3.4 miles, and is located near Aberdeen, Maryland.

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

The Chesapeake Bay was formed about 10,000 years ago when glaciers melted and flooded the Susquehanna River valley.

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

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.

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.

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

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

The area of the watershed is about 64,000 square miles.