Monongahela, referred to locally as Mon City, is a third class city in Washington County, Pennsylvania, United States. It is part of the Pittsburgh, PA Metropolitan Statistical Area, and is located approximately 17 miles south of the town proper. The population was 4,300 at the 2010 census. One of only two cities in Washington County, and the second smallest city in Pennsylvania, Monongahela sits at the intersection of Pennsylvania Route 88, 136,... Show more

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