The Duff (or Bunduff) flows for 14 miles from the Glenade valley to the sea. It is joined by the Ballanaghtrillick River, which runs out of the Horseshoe Pass. The bottom 3 ½ miles is most fished. This is a prolific little spate river for salmon. The Duff gets a good run of summer salmon and grilse. The fish start to enter the river at the end of May with the peak of the run in July / August. With good water levels it can fish through to the end of September. The Duff is a spate river that can fish very well given the right conditions, especially after a freshet. Most anglers choose the deep pool below the falls close to the sea and consequently this pool can become overcrowded. Once a flood has let fish run the falls there is some good fishing available above the falls and also some good water upstream of the main road