|Origin||Red Wall, Vorarlberg|
|Length||18 kilometres (11 mi)|
|Source elevation||2,390 metres (7,840 ft)|
The Meng River originates from the Red Wall mountain gorge at 2,390 metres (7,840 ft) above sea level. It flows through the Gamperdonatal in a northern direction, where it unites in the municipality of Nenzing with the Ill. It reaches a length of 18 kilometers.
The Gampbach with 5 kilometers of length approaches from the right side out of the Gamptal. Gampbach merges in the middle part with the Meng River.