Species of Concern
Wyoming Pocket Gopher (Thomomys clusius)
Wyoming Distribution by County
The U.S. Fish and Wildlife Service determined that listing under the Endangered Species Act is not warranted for the Wyoming pocket gopher (Thomomys clusius) (75 FR 19592, April 15, 2010). We continue to encourage project planners to analyze project areas for potential effects to Wyoming pocket gophers and their habitats. We also ask the public to continue to submit to us any new information that becomes available concerning the status of, or threats to, the Wyoming pocket gopher or its habitat.
Wyoming pocket gophers (Thomomys clusius) are powerfully built mammals, characterized by a heavily muscled head without a noticeable neck, strong front limbs with long nails used for digging, small ears, small eyes, and fur-lined cheek pouches used to carry food. Adult Wyoming pocket gophers typically have a body length (not including the tail) of 4.4 to 5.3 inches, and a weight of 1.6 to 2.5 ounces. The Wyoming pocket gopher is genetically unique from other pocket gophers in Wyoming and can be differentiated from other pocket gophers in its geographical range by being smaller and paler, with a yellow cast to the coat, especially in younger animals. The dorsal coat is uniform in color, and the margins of the ears are fringed with whitish hairs.Very few individuals have been captured to date, with all occurrences in Sweetwater and Carbon counties. The Wyoming pocket gopher is believed to occur primarily in small ‘islands’ of low or sparsely vegetated areas found interspersed within sagebrush habitats. These islands are characterized by having less Artemisia tridentata (Big sagebrush), more Krascheninnikovia lanata (winterfat), more Atriplex gardneri (Gardner’s saltbush), more bare soil, less litter, and fewer surface rocks than the surrounding area. For more information, please visit the Wyoming Natural Diversity Database website at
April 15, 2010 12-Month Finding
February 10, 2009 90-Day Finding