The division of pocket gophers (Geomyidae, Rodentia) into many subspecies has been criticized frequently in recent years. The history of the nomenclature and taxonomic practice in one complex of species of the genus Thomomys is analyzed, and continuous progress is apparent. Studies of Thomomys in Chihuahua, Mexico, are summarized. Thomomys baileyi is synonymized with Thomomys bottae. T. bottae is not conspecific with T. umbrinus. More field work is needed since inadequate material, rather than the concept of subspecies, has limited advances in knowledge of gopher classification and relationships.