استردیلن

Also known as Østerdal, Osterdalen, Osterdal

Østerdalen () is a valley and traditional district in Innlandet county, in Eastern Norway. This area typically is described as the large Glåma river valley as well as all its tributary valleys. Østerdalen is often subdivided into Nord-Østerdal in the north, and Sør-Østerdal in the south. The more mountainous northern half of Østerdalen includes the municipalities of Rendalen, Alvdal, Folldal, Tynset, Tolga, and Os. The more forested southern half includes the municipalities of Elverum (which includes district's largest town, Elverum), Stor-Elvdal, Engerdal, Trysil and Åmot. Østerdalen historic