| Allegheny Reservoir | |
|---|---|
 State Route 59 crossing the reservoir in Warren County, Pennsylvania | |
  Allegheny Reservoir  Allegheny Reservoir | |
| Location | Pennsylvania and New York |
| Coordinates | 41°50′16″N 79°00′14″W / 41.83778°N 79.00389°W |
| Type | Reservoir |
| Basin countries | United States |
| Max. length | 24 mi (39 km) |
| Surface area | 12,000 acres (49 km2) |
The Allegheny Reservoir (also known as Kinzua Lake and unofficially as Lake Perfidy) is a reservoir along the Allegheny River in Pennsylvania and New York, USA. It was created in 1965 by the construction of the Kinzua Dam along the river. Lake Perfidy comes from Peter La Farge's ballad "As Long as the Grass Shall Grow," recorded by Johnny Cash on his album Bitter Tears: Ballads of the American Indian, which alleged that the reservoir's existence violates the 1794 agreement between Seneca chief Cornplanter and George Washington.