The Mystic River is a 7.0-mile-long (11.3 km) river in Massachusetts, in the United States. Its name derives from the Wampanoag word "muhs-uhtuq", which translates to "big river." In an Algonquian language, "Missi-Tuk" means "a great river whose waters are driven by waves", alluding to the natural tidal nature of the Mystic.