valleys. Dale-Gudbrand settled in Hundorp, Sør-Fron. At the time of Halfdan the Black there was a "chief Gudbrand north in Gubrandsdalen" (Gudbrand herse nord i Dalom). Later Eric Bloodaxe had an opponent called Dale-Gudbrand. According to the sage Olaf II of Norway met one Dale-Gudbrand, supposedly the last Dale-Gudbrand, in 1021. Historians believe there was a regional centre at Hundorp during the Viking era and that the name Gudbrand was used for many generations by the ruling family. Burial mounds (tumulus) at Hundorp suggest that powerful men are buried there. Geography The Gudbrandsdalen valley includes the most arid area in Norway. At Skjåk the average annual precipitation is only . The valley sits in the rain shadow of the mountains west (including Jotunheimen), north, and east of the valley. The valley is less incised than the valleys of western Norway. Farming is mostly confined to the relatively narrow areas along the rivers. Gudbrandsdalen and adjacent valleys are surrounded by wide uplands and mountain plateaus traditional used as seter or summer farms. In July 1789 the Storofsen flood disaster occurred and Gudbrandsdalslågen overflooded. This is the largest flood recorded in Norway and the valley was particularly affected. 61 people perished. About 3000 houses were totally damaged and some thousand livestock drowned. All bridges disappeared. Lågen rose up to above its normal level and covered most of the valley floor. A number of farmers abandoned their damaged farms and settled in Målselv, Troms county. The second largest flood occurred in the summer of 1995 and again the valley floor was largely covered by water. After Storofsen the valley floor upstream from Sel Church changed into bogs and shallow lakes because stone and gravel changed the flow of Lågen. From around 1910 drainage efforts left some of dry farmland on what is still known as the Sel bogs. The toxic cicuta virosa thrived on those bogs before they were drained and are known in Norwegian as selsnepe (literally Sel turnip). The valley floor in Lesja (between Dombås and Lora) were originally covered by a shallow lake. Drainage efforts from 1860 abolished the lake and left some of farmland. The central part of the valley is covered by the Losna lake, some deep. Geology The valley of Gudbrandsdalen is of considerable antiquity considering the overall development of the relief of Norway. The valley runs across the height axis of the southern Scandinavian Mountains —a