From A Wiki of Ice and Fire
The Widow's Wash is a stream in the riverlands in the border region between House Bracken and House Blackwood. It has islands in it.
A Dance with Dragons
During the resolution of the siege of Raventree, Lord Jonos Bracken asks Ser Jaime Lannister for the east bank of the Widow's Wash from Crossbow Ridge to Rutting Meadow and all the islands in the stream for subduing Lord Tytos Blackwood. Jaime agrees to the transfer of Crossbow Ridge but not the rest of the shore.
After leaving Raventree, Jaime's column follows the Widow's Wash until dusk, when they cross a shallow ford and take shelter in nearby Pennytree.
- ↑ 1.0 1.1 A Dance with Dragons, Chapter 48, Jaime I.