| Mattmarksee | |
|---|---|
| Location | Saas Valley, Valais |
| Lake type | reservoir |
| Catchment area | 37.10 km² |
| Basin countries | Switzerland |
| Max. length | 3.2 km |
| Surface area | 1.76 km² |
| Max. depth | 93 m |
| Water volume | 10.5 mio m³ |
| Surface elevation | 2197 m |
Mattmarksee is a reservoir in the Saas Valley of the Canton of Valais, Switzerland. The Mattmark dam was built from 1960-1965. The lake's surface area is 1.76 km².