| Sumas River | |
|---|---|
 Sumas River near the town of Nooksack, 2017 | |
| Location | |
| Country | Canada, United States |
| Province | British Columbia |
| State | Washington |
| Physical characteristics | |
| Source | Sumas Mountain |
| • coordinates | 48°52′40″N 122°18′32″W / 48.87778°N 122.30889°W[1] |
| Mouth | Fraser River |
• coordinates | 49°9′N 122°7′W / 49.150°N 122.117°W[2] |
| Length | 58 km (36 mi)[1] |
The Sumas River is a river in the Fraser Lowland and a tributary of the Fraser River system, coursing across the international border between the Canadian province of British Columbia and the U.S. state of Washington.