The Rothay is a spate river of the Lake District in north-west England. Its name comes from Old Norse and translates literally as the red one. This has come to mean trout river. It rises close to Rough Crag above Dunmail Raise at a point about 1542 feet above sea level. Its catchment area covers Grasmere Common including Easedale Tarn, the southern flanks of Fairfield, and several of the fells to the east of Dunmail Raise, including Great Rigg, Rydal Fell, Scandale Fell and Heron Pike.