ABSTRACT Geomyids have been recovered from 1,693 m of section, temporally ranging from mid-Blancan (Pliocene) to early Irvingtonian (Pleistocene). They are represented by Geomys (Nerterogeomys) anzensis n. sp., G. garbanii, and Thomomys sp. The new species resembles G. (Geomys) arenarius in size and proportions of the skull, possibly implying an ecomorphic relationship. The difference in size between G. anzensis and G. garbanii may explain the coexistence of these two species through a large part of the stratigraphic section, by implying two different pocket gopher habitats.