Casselman River Watershed
The Casselman River Watershed is approximately 336,000 acres, with 58,588 acres (17.5% of the total watershed) located in northern Garrett County.
The Casselman River flows north from Garrett County into the Youghiogheny River at Confluence, Pennsylvania. The Youghiogheny River then flows into the Monongahela River in McKeesport, Pennsylvania. The Monongahela River then flows into the Ohio River in Pittsburgh, Pennsylvania. The Ohio River then flows into the Mississippi River at Cairo, Illinois. The Mississippi River flows into the Gulf of Mexico at the Mississippi River Delta in Louisiana.