It flows through the autonomous community of Cantabria and discharges into the Asón River.

The river's name comes from the plains where it is born, known as La Gándara, under the Becerral crag.

It flows from west to east until it reaches the Bolea and Regules bridge, where it changes direction towards the north.

In some areas, it detours round steep mountains; sometimes it plunges from considerable heights.

The river is also known for various caves such as the Cueto-Coventosa ,Tibia-Fresca, Tonio-Cañuela and the Sistema Gándara.