Fine-grained volcaniclastic strata exposed along the Sevier River southeast of Panguitch, Garfield County, southwestern Utah, represent a record of basin fill preserved in a graben. Rodents recovered from this unit include the heteromyid cf. Perognathus sp. indet., the cricetid Baiomys minimus, and the arvicolid Cosomys sp., cf. C. primus. These species, especially the latter two, suggest a Pliocene age (= Blancan North American Land Mammal Age [NALMA]). This marks a previously unknown episode of basin fill in the area; however, the original extent of the strata is poorly constrained.