Monocacy River

Course of the Monocacy River

The Monocacy River in Frederick County

The Monocacy River is a 93.3 km long river in the U.S. states of Maryland and Pennsylvania and the largest tributary of the Potomac River in Maryland.

The Monocacy rises in Adams County and flows between Tuscarora and Dickerson in the Potomac River. The river drains an area of 1927 km ². Largest city on the banks is Frederick. The name comes from the Shawnee Monocacy and means " river of many loops ". The river crosses the Monocacy National Battlefield. There the battle at Monocacy took place in 1864 during the Civil War.

• River in North America
• River in Maryland
• River in Pennsylvania
• River system Potomac River