| Unadilla River Tianadara | |
|---|---|
 Historic marker of the Unadilla River | |
  Location of the mouth of Unadilla River | |
| Location | |
| Country | United States |
| State | New York |
| Region | Central New York |
| Physical characteristics | |
| Source | |
| • location | NE of Millers Mills |
| • coordinates | 42°55′57″N 75°01′39″W / 42.93250°N 75.02750°W |
| Mouth | Susquehanna River |
• location | Sidney |
• coordinates | 42°19′00″N 75°24′36″W / 42.3168°N 75.4100°W |
• elevation | 961 ft (293 m) |
| Length | 71 mi (114 km) |
| Basin features | |
| Progression | Unadilla River → Susquehanna River → Chesapeake Bay → Atlantic Ocean |
| Tributaries | |
| • left | Campbell Brook, Wharton Creek, Butternut Creek, Rogers Hollow Brook |
| • right | North Winfield Creek, West Branch Unadilla River, Button Creek, Beaver Creek, Tallette Creek, Center Brook, Mill Brook, Great Brook, White Store Brook, Kent Brook, Guilford Creek, Peckham Brook |
The Unadilla River is a 71-mile-long (114 km)[1] river in the Central New York Region of New York State.[2] The river begins northeast of the hamlet of Millers Mills and flows generally south to the village of Sidney, where it converges with the Susquehanna River, which drains into the Chesapeake Bay,[3] a bay of the Atlantic Ocean.
Most of the length of the Unadilla forms the western border of Otsego County and the eastern borders of Chenango and Madison counties, all in New York. This border made up a significant portion of the Fort Stanwix Treaty Line of 1768. It was meant to establish the border for an Indian reserve, beyond which European-American settlers were not supposed to go. Settlers resented British efforts to control their movements, and continued to encroach on Native American territories.[4]
