The area northeast of Lake Thingvallavatn was called The Blue Forest in ancient times. The Book of Settlements mentions the farmstead Skalabrekka in The Blue Forest. It also places one of the chieftains, Grimkell, there, and according to the Hardar Saga he lived near Lake Olfusvatn (Thingvallavatn), but later moved to the farm Olfusvatn.

During the latter part of the middle ages some sources mention ruins of a farm on the outskirts of the home meadows of the farm Krokur in the Grafningur area. Long after Grimkell lived at Olfusvatn a man named Olkofri, who brewed and sold alcoholic beverages, med, to the people, who assembled during the two weeks’ session of the parliament every summer, lived in The Blue Forest at the farm Thorhallsstadir, which stood very near the much younger farm Skogarkot.

Other old sources give the impression that The Blue Forest was the much frequented mountain trail between the valley Reykjadalur sydri (now Lundareykjadalur in the West) and the Thingvellir area.