Undersviks FVF is located along road 83 about 25 km north of Bollnäs. The area is divided by Ljusnan.

Ljusnan forms Orsjön with a maximum depth of 64 m which is part of the association's waters, an eldorado for trolling for large pike, pike-perch or trout, in winter lovely bays for catching perch etc. The association has nice put & take waters on both sides of Ljusnan. On the west side Bergtjärn with char and rainbow trout, and on the east side Abborr- and Åltjärn, with trout and rainbow trout. Simeån with its abundant stock of trout. Stora Dalsjön with abundant pike and large perch, as well as pike-perch. Simsjön and parts of Valåsjön with abundant pike and perch.