Beaver County is located in the southwest part of the state of Pennsylvania. Bordering Lawrence County on the north, Butler County on the east, Allegheny County on the southeast, Washington County on the south, and the states of Ohio and West Virginia on the west. Beaver County was carved out of Washington and Allegheny Counties in 1800. In the mid 1800's, a portion of north Beaver County was incorporated to form part of what is now Lawrence County.