The 30 kilometres wide mountain area South of Rondane nationalpark is called Ringebufjellet. It runs from Ringbu in Gudbransdalen to Stor-Elvdalen in Østerdalen. The area's is based on a sparagmite formation in southern central Norway. Imsdalen is situated in the southwestern corner of this area and runs 35 kilometre's in direction due northwest. In the northern part of Imsdalen, can be found two lakes - All in all, they are about 5 kilometres and at their deepest circa 50 meter. The river that runs from the southern lake, is termed Imsa, and it runs trough the remainder of Imsdalen before it reaches Glomma 5 kilometres south of Stai. The name is though to have been formed be the adjective "Ymis" which means changing. Most parts of Ringebufjellet do not have wood, as trees do not grow in these heights above sealevel. Imsdalen, however, has a continuos wood running through it. Some "sæters" (pronounced: s æ t e r - 'The "Æ" vowel is close to the "a" in "shall") are situated in the area around Imsdalen - all at approx. 800-900 meters above sealevel.

The first population of Imsdalen, tentatively, dated back to 1100 AD. When the "birkebeinerne" came in 1206 AD, surely there must have been a suitable barn here to provide shelter for them. Then there weren't any territorial limits between Gudbrandsdalen and Østerdalen, and all were free to hunt and fish in the area.

After the territorial limits between the Gudbrandsdalen and Østerdalen were set, hunters and fishermen from the Gudbrandsdalen and Østerdalen have since kept their interest in the area. In the early days, however, survival was the main reason for hunting and fishing, and boarders were not that respected and defining as they are today. Hunting and fishing in Imsdalen was thriving up to "The Black Plague" in 1349 which had an immense effect on Norway as well as entire Europe, reducing the population of Norway dramatically. Only after 200-300 years later did the population grow back to the same level. The animal graves of Imsdalen were in use to 1730, it is estimated. The first recorded population, that we are certain about, is people from Stor-Elvdalen settling in Imsdalen about 1683. In 1830 there were 5 households in Imsdalen. They probably got their iron from Hirkjølen. Imsdalen and Hirkjølen have been the property of the Norwegian State since early days. The two areas together size up to about 220 000 dekar. Of which Imsdalen is the largest measuring 125 000 dekar and Hirkjølen 95 000 dekar.