The
Rein da Tuma is a river in
Switzerland, in the
Canton of Graubünden. It rises east of the
Rossbodenstock with two or three mountain streams, that flow across the Tuma Alp into the
Lake Toma (German:
Tomasee,
Romansh:
Lai da Tuma). Before reaching the lake, it flows through a plain and forms small
meanders. The Rein da Tuma flows out of Lake Toma on the north east and flows as
Anterior Rhine past the village of
Tschamut in the municipality of
Tujetsch.