The shrew flea, Corrodopsylla curvata curvata (Rothschild, 1915) (Siphonaptera: Ctenophthalmidae), is not common in collections of fleas from the Southwest or Rocky Mountains. Fewer records are from nests than trapped hosts. In 1993, a live female specimen was found in a nest that belonged to an unknown small mammal in the southern Sangre de Cristo Mountains of New Mexico. A 67km extension of range was measured from the nearest of four trap sites in the Jemez Mountains, Sandoval County. The nest site was east-southeast across the Rio Grande in Dalton Canyon, Pecos River watershed, San Miguel County. The nest, its contents, and habitat were described. In addition, we reviewed nonpublished ecological data from each of the three collections from trapped hosts in the Jemez Mountains, 1970–1971, and provided a distribution map. A review of records of C. c. curvata and C. c. obtusata (Wagner, 1929) in western mountains with emphasis on small samples from a canyon in Montana suggested that larger samples would confirm the absence of a zone of intergradation between two allopatric species.