A very shallow, nutrient-poor lake in the upper part of the River Indal system, partly surrounded by marshy areas and with a sandy ridge along one 2 km stretch of shoreline. The confluence of two rivers at the western end of the site has formed the Handol delta and there are other deltas to the north-west and south-east. The lower River Handolan contains rapids, waterfalls, and gorges; there is extensive forest nearby. `Other' land-use (below) is grazing land for reindeer Rangifer tarandus.
The IBA is very important for a variety of breeding waterbirds, raptors, grouse and waders. Breeding birds include nine out of the 32 species in Europe that are restricted (when breeding) to the Arctic/tundra biome.
BirdLife International (2018) Important Bird Areas factsheet: Lake Ånn – Storlien. Downloaded from http://www.birdlife.org on 18/12/2018.