This squirrel inhabits rocky desert in southern Baja California and on Espíritu Santo and San Marcos islands. Its summer back fur tends to be dark and rufous, and its tail underside has alternating black and white bands.
The species account describes the mid-dorsal summer pelage as tending to be among the darker and more rufous in the genus; specimens from the eastern edge of the Vizcaíno Desert and the Llano de Magdalena are lighter and less rufous. The underside of the tail has two black bands alternating with three white bands.
It inhabits generally rocky desert. Its Baja California Sur range is described from the Cape Region to the eastern edge of the Vizcaíno Desert, excluding the higher-elevation conifer forests of the Sierra Laguna.
An extinction-risk assessment has not been added yet.