This species is associated with sandy soils; it is found in an extremely arid region in habitats characterized by soil consisting almost entirely of sand and by sparse vegetation; it prefers flat areas, and is less common on slopes and ridges. Mounds and burrows of this species were found far up arroyos having a sandy floor, suggesting sandy soil is a more significant aspect of the habitat than a flat, open environment (Lackey 1991). The only known predator of C. arenarius is the barn owl, Tyto alba (Lackey 1991).

A female with two embryos was found in March (Lackey 1991).

The range of C. arenarius includes all of the State of Baja California (northern half of the peninsula) and the northern 80% of the State of Baja California Sur (from La Paz northward, including the driest areas) and Magdalena Island, Mexico (Álvarez-Castaneda and Rios 2011). It does not include the coastal areas as previously considered by Hall (1981) and Patton and Álvarez-Castañeda (1999). This species is not found in any localities with foggy desert scrubland (Álvarez-Castaneda and Rios 2011).

Part of the range of this species falls within several protected areas.