Twin Sisters Mountain (Nooksack: Kwetl’kwítl’ Smánit, "red mountain")., commonly called the Twin Sisters, is a mountain in the U.S. state of Washington. Part of the Cascade Range, it lies just southwest of Mount Baker. Of its two main peaks, South Twin is higher, with a summit elevation above 7,004 feet (2,135 m). The summit of North Twin is above 6,644 feet (2,025 m).