Sumas Lake (Halq’eméyle: Semá:th Lake, Nooksack: Semáts Xácho7, (Level Place Lake).,) was a shallow freshwater lake surrounded by extensive wetlands that once existed in eastern Fraser Lowland, located on the south side of the Sumas River between the foothills of the Sumas Mountain (not to be confused with its same-named American sister) and Vedder Mountain. It disappeared after being artificially drained for flood control and land reclamation in the early 1920s, leaving behind a low-lying flatland known as the Sumas Prairie, which is nowadays drained by the Saar Creek (a lower tributary of the Sumas River) and the namesaked Sumas Drainage Canal.