Oulankajoki

Oulankajoki is a river that flows through Finland and Russia. Its name in Finnish is Oulankajoki, and in Russian, it is referred to as Kolosjoki (Колосъёки). The river originates in Russia and flows for approximately 120 kilometers (75 miles) before crossing into Finland. Within Finland, it continues for about 50 kilometers (31 miles).

The Oulankajoki is a significant part of the Oulanka National Park in Finland, a protected area known for its rugged landscapes, rapids, and diverse flora and fauna. The river's course is characterized by numerous rapids and small waterfalls, making it a popular destination for kayaking and canoeing enthusiasts. Its waters are relatively clear and are home to various fish species.

The river's watershed is part of the larger White Sea basin. Historically, the Oulankajoki and its surrounding areas have been sparsely populated, with human activity primarily focused on forestry and some traditional land use. The unique geological formations along its banks, such as canyons and eskers, contribute to its scenic beauty. The river plays an important ecological role, supporting the natural habitats within the national park and contributing to the regional hydrology.