Headwaters/source: Town of New Castle, 1.75-acre pond
Mouth: Yonkers into the Hudson River at Dock Street
Length: About 20 miles
Watershed basin: 26.5 square miles
Average width of Watershed Basin:1.4 miles
Average width of River: 8-12 feet
Average slope of the river: 22 feet/mile
Population in watershed: Approx. 110,000
Population density: 4,151 per square mile, nearly twice the density in all of Westchester and 10 times that of New York State
Original name origin: The river originally was called the Nepperhan, from the Native American word for “rapid little stream.”
Current name origin: The Saw Mill River got its present name from the saw mill that was built near its mouth at Philipse Manor Hall in Yonkers in the mid-1600s.
Hudson River tributary: The Saw Mill River is one of 65 tributaries in the Hudson River watershed and lies completely within Westchester County.
The Saw Mill River Parkway parallels the river for about 16 miles and was constructed between 1925 and 1954.
Tributaries: Tertia Brook, Nannyhagen Brook, Mine Brook, Rum Brook, other numerous unnamed tributaries.
