 Selfoss was settled by Þórir Ásason sometime after 1000; however, the Icelandic sagas mention that Ingólfur Arnarson was here during the winter of 873-74 under the Ingólfsfjall mountain, which is west of the Ölfusá river.In the summer of 1891, due to the lobbying of Tryggvi Gunnarsson, a member of the Alþing, the first suspension bridge was built over the Ölfusá.This was a major breakthrough in Icelandic infrastructure.