The Otta river flows through the Ottadal valley in the municipalities of Skjåk

Skjåk

Skjåk is a municipality in Oppland county, Norway. It is part of the traditional region of Gudbrandsdal. The administrative centre of the municipality is the village of Bismo...

, Lom

Lom, Norway

Lom is a municipality in Oppland county, Norway. It is part of the traditional region of Gudbrandsdal. The administrative centre of the municipality is the village of Fossbergom....

, Vågå

Vågå

Vågå is a municipality in Oppland county, Norway. It is part of the traditional region of Gudbrandsdal. The administrative centre of the municipality is the village of Vågåmo....

 and Sel

Sel

Sel is a municipality in Oppland county, Norway. It is part of the traditional region of Gudbrandsdal. The administrative centre of the municipality is the town of Otta....

 in Norway

Norway

Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...

.

The river Otta begins in Skjåk municipality and flows into lake Vågåvatn

Vågåvatn

The Vågåvatn lake is located in Lom and Vågå municipalities, Oppland county, Norway. The river Otta, which begins in Skjåk municipality, flows into lake Vågåvatn...

. Exiting the Vågåvatn at Vågåmo

Vågåmo

Vågåmo is the administrative centre of Vågå municipality, in Oppland county. Norway. Its population is 1,463. The village is located at the outlet of Lake Vågåvatn in the Otta valley...

, it continues its journey through the Ottadal

Ottadal

Ottadalen is a valley in the municipalities of Skjåk, Lom, Vågå and Sel in the county of Oppland, Norway.Ottadalen is one of the lateral valleys of Gudbrandsdalen. Others include Gausdal, Heidal, and Vinstradal. It lies on the northern edge of Jotunheimen National Park...

 leaving Vågå municipality to meet the Gudbrandsdalslågen

Gudbrandsdalslågen

The Gudbrandsdalslågen river flows through the Gudbrandsdal of Norway.The Gudbrandsdalslågen begins in the lake Lesjaskogsvatnet , which lies in Lesja municipality in Oppland. Lesjavatn is the only lake in Norway which has two outlets; they flow into two of Norway’s more famous rivers...

 at the town Otta

Otta, Norway

is a town in the municipality of Sel in the county of Oppland in Norway. It has about 2,750 inhabitants. The Otta river joins the Gudbrandsdalslågen river at Otta. Next to Otta lies the massive Rondane, which became the first national park in Norway in 1962, and which has several mountains over...

 in Sel municipality.

The watershed of the Otta drains an area of 3948 km².

The name

The name of the river is probably derived from the Norse verb ótta 'scare, terrify'. The water of the river comes from glacier

Glacier

A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

s, and the flooding of the river can be strong and fiercely.