Glerá has its source in the mountains on both sides of Glerárdalur and it falls through the valley a long distance to the sea. Droughts can affect the fishing in Glerá, as with most of the smaller rivers in this area. However, there can often be good fishing despite the amount of water and the length of the river. The fishing has mostly been just over 80 salmon, but usually around 60 – 70 are caught. The main fishing spots are Foss, Klapparhylur, Grjótgarður og Leirubakki. Also, Símastrengur and Grænibakki in sufficient water levels.