The Monongahela City Bridge spans the Monongahela River from the City of Monongahela in Washington County, Pennsylvania to Forward Township in Allegheny County, Pennsylvania. It was constructed to replace a bridge which was 1/4 of a mile north of its location at First and Main Streets, and it opened to traffic in 1990.The bridge marks the end of Monongahela's Main Street and the separation of State Route 136 from State Routes 88 and 837.