- Southern Terminus:
- Bear Mountain Bridge (US 6/US 202) in Peekskill
- Northern Terminus:
- South Road (US 9) in Wappingers Falls
- 25.21 miles
- Westchester, Putnam, Dutchess
NY 9D is a north/south route running along the Hudson River from the Bear Mountain Bridge (US 6/US 202) to Wappingers Falls. It runs parallel to and a couple of miles west of US 9. In most areas, it is a two-lane undivided road, although there are some short sections where it is wider. The one and only mountain tunnel in the state is located along NY 9D near the Putnam-Dutchess county line.