Sources of the Rhine

Lake Toma in the Swiss canton of Grisons (Graubünden) is generally regarded as the Source of the River Rhine. The lake's outflow, the Rein da Tuma, subsequently becomes the Anterior Rhine (Sursilvan: Rein Anteriur; German: Vorderrhein), which later confluences with the Posterior Rhine (Sutsilvan: Ragn Posteriur; German: Hinterrhein) to form the Rhine (Alpine Rhine). Because the tributary systems of the Rhine differ only slightly in length, discharge and the size of their drainage areas, it is difficult to pinpoint a single source of this major European river.