Eastern Massasauga (Sistrurus catenatus) is a State Endangered Species and a Federally Threatened Species. This rattlesnake is strongly associated with floodplain habitats along medium to large rivers, especially near river confluences, where they primarily occupy open canopy wetlands, such as sedge meadows, fresh wet meadows, shrub-carrs, and adjacent upland prairies, floodplain forests, and old fields. Overwintering usually occurs in terrestrial crayfish burrows or rotted out root channels in open canopy wetlands, shrub-carrs, and lowland hardwood forests. Massasaugas begin to emerge in spring, usually in early-April, from overwintering habitats. They can remain active until mid-November, depending on air temperatures. This species breeds primarily in August and females give birth in late-July or August the following year. For land management activities with the potential to impact this species, please refer to the Eastern Massasauga Land Management Guidance document. If you have a project that may impact this species, we encourage you to consult with your District Ecologist or an NHI Zoologist for specific site recommendations as there are very few known occurrences of this species in the state.
