Deer Creek is a 52.9-mile-long (85.1 km)[1] river in Maryland and Pennsylvania that flows through the scenic areas of Harford County and empties into the Susquehanna River, roughly halfway between the Interstate 95 bridge and Conowingo Dam.
[2] Its watershed area in MD (excluding water) is 145 square miles (380 km2), with 3% impervious surface in 1994.
Deer Creek rises in Shrewsbury in York County, Pennsylvania, and flows southeast, soon entering Maryland.
A Denil (baffle) fish ladder was built beside the dam in 2000, re-opening approximately twenty-five miles of spawning habitat to several anadromous fish species.
The Deer Creek Bridge, Stewartstown Railroad carries the Stewartstown Railroad over Deer Creek in Hopewell Township and Shrewsbury Township, Pennsylvania.