Ounasjoki

The Ounasjoki River () is the Kemijoki River's largest tributary and is Finland's longest single river tributary. It is also the largest river entirely within its borders. Ounasjoki is approximately in length, and the catchment area is , 27 percent of the Kemi catchment area.
Course.
The Ounasjoki River originates at Ounasjärvi Lake in Enontekiö. It flows first eastwards through Lake Periläjärvi and turns south after some seven kilometres. The river then follows southern-southeasterly course until its confluence with the Kemi River at Rovaniemi.
Fauna.
Grayling, trout, pike and other fish typical to northern Finland are found in the Ounasjoki.