We studied the overwintering behavior of common musk turtles (Sternotherus odoratus) near the northern edge of the species' range using radiotelemetry. The turtles (n = 6) were found under the ice in winter in shallow (< 2 m) water, above sediments, in locales with abundant aquatic vegetation, and temperatures ranging between 0.4° and 1.7°C. American mink (Mustaela vison) appear to have killed 6 of the 9 radiotagged turtles, and 13 other common musk turtles in the same area during the winter, indicating that winter predation is an important source of mortality in this species.