The western blind snake is pink, purple, or silvery-brown in color, shiny, wormlike, cylindrical, blunt at both ends, and has light-detecting black eyespots.

The skull is thick to permit burrowing, and it has a spine at the end of its tail that it uses for leverage.

In Mexico its distribution includes the Mexican states of Baja California, Sonora, Sinaloa, Nayarit, Jalisco, Colima, Chihuahua, Durango, Coahuila, Tamaulipas, and San Luis Potosí.

The type locality was restricted by Klauber (1931) to "vicinity of Vallecito, eastern San Diego County, California," and by Brattstrom (1953) to "the Upper Sonoran Life Zone of the Vallecito area".

[2] R. humilis lives underground, sometimes as deep as 20 metres (66 ft), and is known to invade ant and termite nests.