Grønfjellåga

Grønfjellåga (lit. "the river of the green mountain") is a river in the municipality of Rana in Nordland county, Norway. The 17 km long river's source is the lakes Kallvatnet and Kopparvatnet. It then flows through the Grønfjelldalen valley while absorbing several smaller rivers, before it flows out as a tributary to the river Ranelva at the Dunderforsen waterfall (also called Stupforsen).

Media gallery
These photos are from a place 3.5 km east of Stupforsen: