The Berkshires is a highland geologic region located in the western parts of Massachusetts

Massachusetts

The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...

 and Connecticut

Connecticut

Connecticut is a state in the New England region of the northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, and the state of New York to the west and the south .Connecticut is named for the Connecticut River, the major U.S. river that approximately...

.

Also referred to as the Berkshire Hills, Berkshire Mountains, and Berkshire Plateau, the region enjoys a vibrant tourism industry based on music, arts, and recreation.
The term "The Berkshires" has overlapping but inidentical political, cultural, and geographic definitions.
Politically, Berkshire County, Massachusetts

Berkshire County, Massachusetts

Berkshire County is a non-governmental county located on the western edge of the U.S. state of Massachusetts. As of the 2010 census, the population was 131,219. Its largest city and traditional county seat is Pittsfield...

 was a governing body formed in 1761; it includes the western extremity of the state, with its western boundary bordering New York and its eastern boundary roughly paralleling the watershed divide separating the Connecticut River

Connecticut River

The Connecticut River is the largest and longest river in New England, and also an American Heritage River. It flows roughly south, starting from the Fourth Connecticut Lake in New Hampshire. After flowing through the remaining Connecticut Lakes and Lake Francis, it defines the border between the...

 watershed from the Housatonic River

Housatonic River

The Housatonic River is a river, approximately long, in western Massachusetts and western Connecticut in the United States. It flows south to southeast, and drains about of southwestern New England into Long Island Sound...

-Hoosic River

Hoosic River

The Hoosic River, also known as the Hoosac, the Hoosick and the Hoosuck , is a tributary of the Hudson River in the northeastern United States. The different spellings are the result of varying transliterations of the river's original Algonquian name...

 watersheds.