Central and southern Utah extending into western Colorado and parts of Arizona.
Frequents a variety of habitats — foothills, prairies, high meadows, and farmland.
Ventrals and chin markings frequently flecked with black. The first white ring is 1 – 4 scales wide at the middorsal line; body rings not expanded middorsally.
Often nocturnal, especially in warm weather. Because these snakes are often found in barnyards where they hunt mice, they have been erroneously accused of milking cows; hence the common name. These snakes are rarely seen as they often hide during the day under boards, rocks, logs and stumps.
Usually 2 to 17 eggs produced.
Snakes that happen upon a mouse nest filled with younce mice will often grasp one mouse with its jaws, and use thier body coils to pin other mice against the burrow walls. This allows them to eat the other mice at their leisure.