From May 1978 through September 1980, baseline data for rodent populations were collected by live-trapping in the Saval Ranch area of northeastern Nevada. The objectives of this study were to determine species composition and relative abundance of rodents for the various range sites. The 3 most abundant and uniformly distributed species were deer mice (Peromyscus maniculatus), Great Basin pocket mice (Perognathus parvus), and least chipmunks (Neotamias minimus). Relative abundance indices and densities reported for most species were similar to those reported in other multiyear studies at similar sites. The composition and relative abundance/density of rodent species was variable among habitats and over time. Diverse rodent species within the sagebrush ecosystem have commensurately diverse habitat requirements that should be considered when vegetation management is planned. Annual population fluctuations and differences among similar habitats should be considered when researchers propose to test rodent population responses to livestock grazing or other habitat treatments.