Wikipedia
Lesjaskogsvatnet
Lesjaskogsvatnet (literally the Lesja woods lake) is a lake which serves as the headwaters for Gudbrandsdalslågen (literally the Gudbrands valley water course) as well as for Rauma River. Gudbrandsdalslågen flows through the Gudbrandsdal valley bottom, ending in lake Mjøsa.
The lake was dammed to serve the Lesja Iron Works in the 1660s. The lak has two outlets: It flows both East into the Gudbrandsdalslågen and west into the Rauma river in the Romsdalen valley.
No. 263 Squadron RAF operated with 18 Gloster Gladiator biplane fighters from a landing strip on the frozen Lesjaskogsvatnet in late April 1940 as part of the Norwegian campaign.