Minnesota Wisconsin Ecological Services Field Office

Midwest Region


Minnesota Wisconsin Field Office

4101 American Boulevard East
Bloomington, MN 55425
Phone: 952-252-0092
Fax: 952-646-2873
TTY: 1-800-877-8339 (Federal Relay)

e-mail: TwinCities@fws.gov



Connect With Us


Facebook icon

Flickr icon
RSS Twitter icon
YouTube icon  



Buy Duck Stamps icon Endangered Species Day icon


Great Lakes Restoration Initiative logo




Plethobasus cyphyus


Sheepnose Listed as Endangered

Sheepnose mussel.

Photo by USFWS; Kristen Lundh


News Release


Sheepnose Information (links to Regional FWS site)


Spectaclecase Information (links to Regional FWS site)


The sheepnose is a freshwater mussel that historically occurred throughout much of the Mississippi River system, with the exception of the upper Missouri River system and most lowland tributaries in the lower Mississippi River system. This species is known from the Mississippi, Ohio, Cumberland, Tennessee, and Ohio main stems, and scores of tributary streams rangewide.


The sheepnose has experienced a significant reduction in range and most of its populations are disjunct, isolated, and appear to be declining rangewide. The extirpation of this species from over 50 streams within its' historical range indicates that substantial population losses have occurred. In the vast majority of streams with extant populations, the sheepnose appears to be uncommon at best. Small population size and/or restricted stream reaches of current occurrence are a real threat to the sheepnose due to the negative aspects of genetics of small, geographically isolated populations.


Sheepnose Candidate Form (PDF)


Sheepnose Status Assessment September 2002 (PDF)



Back to Twin Cities Field Office Endangered Species


Last updated: January 9, 2020