Rochester is a borough in Beaver County, Pennsylvania, United States. It is located at the confluence of the Beaver and Ohio rivers 25 miles northwest of Pittsburgh. The population was 3,472 at the 20

Beaver County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 168,215. Its county seat is Beaver, and its largest city is Aliquippa. The county is part of th