Some great info:)

The Chesapeake Bay is the largest estuary in the United States. It lies off the Atlantic Ocean, surrounded by Maryland and Virginia. The Chesapeake Bay's watershed covers 64,299 square miles (166,534 km²) in the District of Columbia and parts of six states: New York, Pennsylvania, Delaware, Maryland, Virginia, and West Virginia. More than 150 rivers and streams drain into the Bay. The Chesapeake Bay is about 200 miles (300 km) long, from the Susquehanna River in the north to the Atlantic Ocean in the south. At its narrowest point near Annapolis, Maryland, the Bay is 4 miles (6.4 km) wide; at its widest point, near the mouth of the Potomac River, it is 30 miles (50 km) wide. Total shoreline for the Bay and its tributaries is 11,684 miles (18,804 km), and the surface area of the bay and its major tributaries is 4,479 square miles (11,601 km²). The bay is spanned in two places. The Chesapeake Bay Bridge crosses the bay in Maryland from Sandy Point (near Annapolis) to Kent Island; the Chesapeake Bay Bridge-Tunnel in Virginia connects Virginia Beach to Cape Charles. The word Chesepiooc is an Algonquian word commonly believed to mean "Great Shellfish Bay;" however, a reconstruction of Virginian Algonquian implies that the word may mean something like "Great Water" or it might just be the name of a village at the mouth of the bay. The Chesapeake Bay is the ria, or drowned valley, of the Susquehanna, meaning that was where the river flowed when sea level was lower. It is not a fjord, as the Laurentide Ice Sheet never reached as far south as the northernmost point on the bay. The Bay was formed starting about 10,000 years ago when rising sea levels at the end of the last ice age flooded the Susquehanna river valley. The Bay's geology, its present form and its very location have also been affected by a bolide impact event at the end of the Eocene (about 35.5 million years ago), forming the Chesapeake Bay impact crater. Parts of the bay, especially the big parts by the coastline of Calvert County, Maryland, are lined by cliffs as the result of receding waters millions of years ago. These cliffs, generally known as Calvert Cliffs, are famous for their fossils, especially fossilized shark teeth, which are commonly found washed up on the beaches next to the cliffs. Scientist's Cliffs is a beach community in Calvert County, named so because of the cliffs' propensity for geological finds and numerous fossils. Much of the bay is quite shallow. At the point where the Susquehanna River flows into the bay, the average depth is 30 feet (9 m), although this soon diminishes to an average of 10 feet (3 m) from the city of Havre de Grace for about 35 miles (56 km), to just north of Annapolis. On average, the depth of the bay is less than 30 feet or 9 meters; over 24% of the bay is less than 2 m (6.6 ft) deep. The climate of the area surrounding the bay is primarily humid subtropical, with hot, very humid summers and cold to mild winters. Only the area around the mouth of the Susquehanna River is continental in nature, and the mouth of the Susquehanna River and the Susquehanna flats often freeze in winter. It is exceedingly rare for the surface of the bay to freeze in winter, as happened most recently in the winter of 1976-1977. Since the bay is an estuary, it has fresh water and brackish water. Brackish water has 3 salinity zones, oligohaline, mesohaline, and polyhaline. The salinity is measured on parts per thousands (ppt). The fresh water zone runs from the mouth of the Susquehanna River to north Baltimore. The oligohaline zone has very little salt. Salinity varies from 0.5ppt-10ppt and freshwater species can survive there. The north end of the oligohaline zone is north Baltimore and the south end is the Chesapeake Bay Bridge. The mesohaline zone has a medium amount of salt and runs from the Bay Bridge to the mouth of the Rapahannock River. the salinity ranges from 10.7ppt-18ppt. The polyhaline zone is the saltiest zone and some of the water can be as salty as sea water. It runs from the mouth of the Rappahannock River to the mouth of the bay. The salinity ranges from 18.7ppt-36ppt. 36ppt is as salty as the ocean.

Doggy heaven @ Chesapeake Bay