Where is he located in the 1920 census?
Osterdalen is a large valley. It consists of the municipalities Rendalen, Alvdal, Folldal, Tynset, Tolga, Os, Elverum, Stor-Elvdal, Engerdal, Trysil and Åmot.
Foss could also be a short form of Fossum (Elverum); Fossvolgen (Tolga); Fosbakken (Tynset); etc.