Eastern Massasauga Rattlesnake


Scientific Name: Sistrurus catenatus
Size: 18.5 – 39.5” (adult total length)
Federal Status: Threatened
Michigan State Status: Special Concern
MDNR Wildlife Action Plan Status: Species of Greatest Conservation Need


Eastern Massasauga Rattlesnake


Prefer damp lowland areas, including river bottom woodlands, shrub swamps, bogs and fens, marsh edges, sedge meadows, and moist prairie.

Adult Coloration:

Gray, gray-brown, or brown background with a row of 21 to 40 large dark brown blotches edged in black down the back. Sometimes these blotches are outlined by white or yellow. Two or three rows of dark spots alternate along the sides, with the lowest row running onto the belly scales. Series of alternating dark and light bands around the tail. Dark stripe starts from the eye with a white lower border. Two dark stripes on back of head extend onto neck. Belly usually black mottled with gray, yellow, or white. Occasionally individuals can be melanistic (solid black) with light markings on the chin, throat, and lip.

Adult Characteristics:

Medium-sized, thick bodied snake with a rattle at the tail tip, a pit between the eye and nostril, and catlike pupils. Head is wider at the back and distinct from the neck.

Scale Count:

Usually 25 scale rows at midbody

Species Confused With:

They are commonly confused with hognose snakes, milksnakes, and sometimes even water snakes.


  • Amphibians and Reptiles of the Great Lakes Region by Jim Harding
  • Harding, J.H. and J.A. Holman. 2006. Michigan Snakes. MSU Extension Ext. Bulletin E-2000,74 pp. [revised].
  • Ruthven, A. G., H. B. T. Gaige, et al. 1912. The herpetology of Michigan, by Alexander B. Ruthven. Crystal Thompson and Helen Thompson; Memoranda towards a bibliography of the archaeology of Michigan, by Harlan I. Smith; prepared under the direction of Alexander G. Ruthven. Lansing, Mich., Wynkoop Hallenbeck Crawford, State Printers.
  • Holman, J. A. 2012. The Amphibians and Reptiles of Michigan: A Quaternary and Recent Faunal Adventure. Detroit, Mich., Wayne State University Press.
  • Conant, R., and Collins, J. T. 1998. Reptiles and Amphibians: Eastern, Central North America. Houghton Mifflin Harcourt Press