The Site is situated in the mountainous area of north-west Sweden, where watercourses of two converging valleys join to form a delta in Lake Yraft. The Site comprises a number of lakes, bogs and marshes, as well as riparian forest with Betula woodland and sparse Pinus sylvestris and subalpine birch forest. The southern valley, Tjålmejaure, has many lakes with shallow shores which are important for breeding birds. The northern valley, Laisdalen, is one of the most wildlife-abundant valleys in the Swedish mountain area, and forms an important species distribution corridor into nearby mountainous areas. The Site supports a rich bird life and is an important breeding and staging area for a large number of threatened bird species. Human activities include reindeer farming by indigenous Saami people, forestry, sport fishing, hunting, and hiking. The area from the Yraft delta and downstream Laisälven is of national cultural importance. There are many prehistoric and historic remains in the area, representing a diversity of cultures. It is one of the few alluvial meadow areas that are still managed in the province of Norrbotten, serving as an example of earlier traditional use of wetlands. A long tradition of mowing has provided a favourable habitat for a vast number of plant species.