| Grass Creek | |
| River | |
| Source | Grass Lake |
|---|---|
| Mouth | Black Lake |
| - location | Rossie, New York |
| - elevation | 276 ft (84 m) |
| - coordinates | 44°24′17″N 75°39′31″W / 44.40472°N 75.65861°WCoordinates: 44°24′17″N 75°39′31″W / 44.40472°N 75.65861°W |
| Basin | 10.3 sq mi (27 km2) |
Grass Creek drains Grass Lake and flows north before emptying into Black Lake near Rossie, New York.