Glomma in the context of Glåmdalen

Gudbrandsdalen (Urban East Norwegian: [ˈɡʉ̂ː(d)brɑnsˌdɑːɳ]; English: Gudbrand Valley) is a valley and traditional district in the Norwegian county of Innlandet (formerly Oppland county). The valley is oriented in a north-westerly direction from Lillehammer and the lake of Mjøsa, extending 230 kilometers (140 mi) toward the Romsdalen valley. The river Gudbrandsdalslågen (Lågen) flows through the valley, starting from the lake Lesjaskogsvatnet and ending at the lake Mjøsa. The Otta river which flows through Otta valley is a major tributary to the main river Lågen. The valleys of the tributary rivers such as Otta and Gausa (Gausdal) are usually regarded as part of Gudbrandsdalen. The total area of the valley is calculated from the areas of the related municipalities. Gudbrandsdalen is the main valley in a web of smaller valleys. On the western (right hand) side there are long adjacent valleys: Ottadalen stretches 100 kilometers (62 mi) from Otta village, Gausdal some 50 kilometers (31 mi) from Lillehammer and Heidal some 40 kilometers (25 mi) from Sjoa. Gudbrandsdalen runs between the major mountain ranges of Norway including Jotunheimen and Dovrefjell–Rondane.

Together with the Glomma river and the Østerdalen valley, the river Lågen and the Gudbrandsdalen valley form Norway's largest drainage system covering major parts of Eastern Norway. Gudbrandsdalen is home to Dovre Line railway and the European route E6 highway. The valley is the main land transport corridor through Eastern Norway, from Oslo and central eastern lowlands to Trondheim and Møre og Romsdal.

The Skien watershed is the third largest watershed of Norway after those of the Glomma and the Drammen rivers. The catchment area is 10,780 square kilometres (4,160 sq mi), and the maximum length is 252 kilometres (157 mi).

The Skien watershed includes rivers which feed Lake Norsjø above Skien;

Lesjaskogsvatnet (lit. 'the Lesjaskog lake') is a lake in Lesja Municipality in Innlandet county, Norway. The 4.3-square-kilometre (1.7 sq mi) lake lies in the upper Gudbrandsdalen valley, between the villages of Lesjaskog (on the west end) and Lesjaverk (on the east end). The European route E136 highway and the Raumabanen railway line both run along the north side of the lake.

The lake is unusual by having two outlets, one in each end. It flows east into the Gudbrandsdalslågen river and it also flows out to the west into the Rauma river in the Romsdalen valley. This bifurcation lake serves as the headwaters for two major rivers: Gudbrandsdalslågen (flowing south/east) and for Rauma river (flowing west). Gudbrandsdalslågen (also known as Lågen) flows through the Gudbrandsdalen valley, ending when it flows into the lake Mjøsa. The lake sits on the watershed in the north-western corner of Glomma drainage system that includes large parts of eastern Norway.

Vinger is a traditional district in Innlandet county, Norway. The 1,677-square-kilometre (647 sq mi) district encompasses the lands that make up Kongsvinger Municipality and Eidskog Municipality. It is generally located to the south and east of the town of Kongsvinger and the river Glomma. The main church for the region historically was Vinger Church. The area was once part of Vinger Municipality and it is also included in the Solør, Vinger og Odal prosti which is a deanery within the Church of Norway. This area was also once part of the jurisdictional area of the Vinger og Odal District Court.

The Skien watershed is the third largest watershed of Norway after those of the Glomma and the Drammen rivers. The catchment area is 10,780 square kilometres (4,160 mi), and the maximum length is 252 kilometres (157 mi).

The Skien watershed includes rivers which feed Lake Norsjø above Skien;