Chicago Ecological Services Field Office

Midwest Region


Chicago Field Office

230 South Dearborn St.,

Suite 2938

Chicago, Illinois 60604
Phone: 312-216-4720

FAX: 312-216-1788
TTY: 1-800-877-8339
(Federal Relay)


Map of Chicago Field Office counties of responsibility.




Ecological Services

We work with public and private entities to conserve and restore Chicago metro area endangered species, migratory birds, wetlands, and other important fish and wildlife resources.



For questions about CITES permits, and importing wildlife and wildlife parts, please contact the USFWS Chicago Wildlife Inspection Program (847) 298-3250

Eastern Massasauga Rattlesnake (Sistrurus catenatus)

Listed as threatened

Sept. 30, 2016


Complete regulatory profile as provided by the Service's Endangered Species website.


Status assessment,1998 (1.5mb pdf). 


Questions and answers about the conservation of the eastern massasauga rattlesnake.


Why conserve a venomous snake?


• USFWS eastern massasauga


Current Information from the Service's Endangered Species website, scroll down to see Eastern massasauga rattlesnake.



Image of eastern massasauga rattlesnake, links to "species spotlight page."

This small snake has a broad historical range in the upper Midwest and southern Ontario.  The eastern massasauga rattlesnake is listed as rare, threatened, or endangered by every state or provincial government in it's range.  Habitat destruction has led to much of the decline of this species.  However, because it is venomous, this secretive species has also been deliberately persecuted and killed by people who fear being bitten. 


In 2016 the eastern massasauga was listed as threatened under the Endangered Species Act. Find out more.


Historical Records for this Species in Northeast Illinois

are available from Cook, DuPage, Lake, and Will counties.


The Chicago Illinois Field Office is the lead office for coordinating the Service's efforts to recover this species.  We worked with the Illinois Department of Natural Resources to establish an Illinois Eastern Massasauga Recovery Team.  The multidisciplinary team will work on conserving remaining Illinois populations of this species, and explore whether extirpated populations might be re-established. We also network and consult with species experts and other field offices within the ten states where eastern massasauga is known historically.  In 2007, Chicago's Lincoln Park Zoo became the lead zoo for the Eastern Massasauga Rattlesnake Species Survival Plan, a cooperative process sanctioned by the Association of Zoos and Aquariums (AZA).  We will work closely with AZA to implement the plan. 


This species is listed as endangered by the State of Illinois. In the Chicago region, we have visited all historical localities of the eastern massasauga, and assessed the present condition of available habitat.  We have networked with the Illinois Department of Natural Resources, local land managers and others with an interest in this species so that its needs might be considered in implementing future land management activities.  Finally, we have consulted and worked in the field with massasauga species experts at the Illinois Natural History Survey to become familiar with field protocols and techniques for studying massasauga population biology.


Have You Seen a Massasauga?

This office annually takes numerous phone calls from individuals concerned that they may have found an eastern massasauga.  This species is now extremely rare locally.  However, several other native non-venomous snake species bear a superficial resemblance to the eastern massasauga.  We are interested in reports of eastern massasauga, though confirmation of identity can be difficult.  If possible, individuals who believe they have encountered an eastern massasauga in northeast Illinois are encouraged to take a digital photograph and email it to this office.  Do not attempt to handle a live eastern massasauga, or approach one to a distance of closer than 3-4 feet. 



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Last updated: December 30, 2019