Captain John Smith was the first European to explore the river, noting it on his 1612 map as the Bolus River. The "Red river", named after the clay color, is considered the "old Bolus", as other branches were also labele… See more

The 19.4-mile-long (31.2 km) South Branch rises at Parr's Spring, where Howard County, Carroll, Frederick, and Montgomery counties meet. The latter begins at elevation 780 feet (240 m) on Parr's Ridge, just south o… See more

The Patapsco has a watershed (including the water surface) of 950 square miles (2,460 km ).
• Deep Run (Carroll County)
• Board Run (Baltimore County)… See more

The removal of Bloede's Dam in September 2018, opened up 65 miles (105 km) of the Patapsco River watershed, which will potentially restore spawning runs of at least six species of native anadromous fish: alewife (Alosa … See more