Geographic Variation in Red-backed Mice (Genus Clethrionomys) of the Southern Rocky Mountain Region

The authors examine geographic variation in red-backed mice across the southern Rocky Mountains by analyzing museum specimens and field records to map subspecies distributions and document morphological differences. They recognize two previously unnamed subspecies and clarify the taxonomic status of several named forms, comparing pelage color, dorsal stripe extent, ear and tail characters, and cranial features among populations from different mountain ranges. The paper provides specimen localities and counts, a range map, and discussion of regional variation patterns with taxonomic implications.