Hag's Mire is a village in the northern riverlands and the seat of House Nayland. If one intends to go around the Blue Fork, one must pass through Sevenstreams and Hag's Mire, which is considered full of bogs and bad roads. Hag's Mire is full of green pools and soft ground.
A Storm of Swords
With the fords of the Blue Fork overflowing and the bridges at Fairmarket and Oldstones washed away, King Robb Stark's thirty-five hundred men are forced to ride through Hag's Mire and Sevenstreams on their way from Riverrun to the Twins. While the host is encamped at Hag's Mire, Robb explains his plan to retake Moat Cailin from the ironborn to Catelyn and Edmure Tully, Jason Mallister, Greatjon Umber, Galbart Glover, and Maege Mormont. The attendees are also witnesses to Robb's will.