Isteren is a lake in the municipality of Engerdal, which is in Hedmark county, Norway. Isteren is a nutritious lake with a large diversity of species. It is a popular fishing area, and the chances for the good catch is certainly present. In the summer of 2006, a trout weighing 9,250 kg was caught with a rod from a small boat. It is also rich in whitefish, pike, perch, grayling, burbot and herring.