image courtesy of dave prival

Black-necked Gartersnake
(Thamnophis cyrtopsis) 
The black-necked gartersnake is named for large blotches on either side of its neck. It is a semi-aquatic species and is usually found near a water source. As a defense, black-necked gartersnakes will bite, defecate, and emit a foul smelling musk. Young are live- born. 
Total length: 16 - 46 in (41 - 117 cm) 
Diet: Frogs, toads, tadpoles, fish, lizards

nps/don swann

Coachwhip (Masticophis flagellum) 
The coachwhip is a long, slender snake.  It gets its name from its resemblance to the whip used by stagecoach drivers. It is variable in color throughout its range, but individuals at Saguaro National Park are usually almost completely black. An extremely fast moving snake, the coachwhip quickly seizes its prey and swallows it live. If caught, a coachwhip will become aggressive and may bite repeatedly until released. 
Diet: Small mammals, birds, bird and reptile eggs, lizards, snakes, frogs, insects, carrion

image courtesy of dave prival

Common Kingsnake (Lampropeltis getula) 
A habitat generalist, the common kingsnake is found from deserts to riparian areas to forests.  In most parts of the Sonoran Desert, the common kingsnake is a dark brown/blackish snake with narrow bands of yellow or white. They are opportunistic feeders, but are well known for eating rattlesnakes. Kingsnakes are believed to be immune, or at least extremely tolerant, of rattlesnake venom. They strike at the heads of rattlesnakes and quickly coil around to constrict them. 
Total length: 30 - 85 in (76 - 216 cm)

nps/saguaro national park

Glossy Snake (Arizona elegans) 
The glossy snake is named for its smooth, shiny skin which varies in color from light brown to pinkish-gray.  It occurs in a variety of  habitats but generally prefers open areas with sandy soils.  This snake is a strong burrower, complete with a countersunk lower jaw to prevent sand from getting in its mouth. They constrict their prey, pressing it against a solid surface or swallow it live. 
Total length: 26 - 70 in (66 - 178 cm) 
Diet: mostly lizards but also snakes

image courtesy of dave prival

Gophersnake (Pituophis catenifer) 
A large and heavy-bodied snake, the gophersnake is the longest snake in the west.  They are found in habitats from the Atlantic to Pacific Oceans, and from southern Canada into Mexico. When disturbed, the gophersnake will put on a defensive show.  It may coil up, flatten its head into a triangular shape, hiss loudly, and shake its tail, to appear and sound like a rattlesnake.
Total Length: 76 - 110 in (76 - 279 cm) 
Diet: Rodents, baby rabbits, birds, lizards

image courtesy of dave prival

Long-nosed Snake  (Rhinocheilus lecontei)  The color and pattern of long-nosed snakes vary considerably, but they are usually banded or blotched with red, black, and white.  They have countersunk lower jaws and long snouts, indicating a preference for burrowing.  When attacked or handled, the long-nosed snake writhes and twists its body and defecates to deter predation. 
Total length: 20 - 60 in (51 - 152 cm) 
Diet: Lizards (mostly whiptails) and their eggs, small snakes, small mammals

image courtesy of dave prival

Mountain Patch-nosed Snake
(Salvadora grahamiae) 
This snake looks similar to the western patch-nosed snake, but it is found at higher elevations.  It has a pale, brown dorsal stripe bordered by one dark stripe.  
Total length: 22 - 47 in (56 - 119 cm) 
Diet: Lizards, small snakes, reptile eggs, nestling birds, small animals

nps/saguaro national park

Nightsnake (Hypsiglena torquata) 
A triangular-shaped head often leads people to think that this small snake is a rattlesnake, but closer inspection shows that it has no rattle.  It has vertical pupils and a pair of dark blotches directly behind the head.  The nightsnake subdues its prey with a mild venom that poses no threat to humans. 
Total length: 12 - 26 in (30 - 66 cm) 
Diet: Lizards, small snakes, frogs, salamanders, small mice

image courtesy of eric stitt

Ring-necked Snake (Diadophis punctatus) 
This inconspicuous looking snake is usually an olive green to bluish-gray snake with a yellow or orange neckband.  They are found across the U.S., with western populations preferring moist habitats.  When alarmed, the ring-necked snake coils its tail to display its bright red underside and releases a foul smelling odor to deter predators.  
Total length: 8 - 34 in (20.3 - 8.7 cm) 
Diet: Salamanders, small frogs, tadpoles, lizards, small snakes, insects, earthworms

image courtesy of kevin black

Saddled Leaf-nosed Snake
(Phyllorhynchus browni) 
This snake has an enlarged scale on its snout that looks similar to that of a patch-nosed snake, except that the scale has free edges. It is named for both its nose scale and the dark brown blotches or saddles on its back.  It is found in areas of mixed desert scrub and uses its snout to burrow in search of lizards and their eggs. 
Total length:12 - 20 in (30 - 51 cm) 
Diet: Lizards and their eggs

image courtesy of erin zylstra

Smith’s Black-headed Snake
(Tantilla hobartsmithi) 
As its name implies, this snake has a black cap on top of its head with a cream colored collar.  It frequents brushy areas, especially near canyon bottoms and streams. 
Total length: 5 - 15 in (13 - 38 cm) 
Diet: Centipedes, millipedes, insects

image courtesy of dave prival

Sonoran Mountain Kingsnake
(Lampropeltis pyromelana) 
This beautiful snake has red, black, and white crossbands, with the red bands bordered by thin bands of black.  This harmless constrictor closely resembles venomous coral snakes, and this mimicry might be used as self defense.  A montane species, it is usually found in oak-juniper and pinon-juniper woodlands but may be found at lower elevations in moist canyons.
Total Length: 18 - 42 in (46 - 107 cm) 
Diet: Lizards, snakes, small mammals, frogs

image courtesy of dave prival

Sonoran Whipsnake
(Masticophis bilineatus)  
Similar to the coachwhip, the Sonoran whipsnake is smaller and greenish-gray in color with two or three light colored stripes on each side of its body.  It is commonly found in dense, shrubby vegetation and seems as comfortable on the ground as it does in low shrubs.  The Sonoran whipsnake swallows its food live. 
Total length: 24 - 67 in (61 - 170 cm) 
Diet: Birds, small mammals, lizards, snakes, frogs 

nps/saguaro national park

Variable Sandsnake
(Chilomeniscus stramineus) 
This small snake is one of the most efficient “sandswimmers.”  Its adaptations for burrowing include a narrow head, a deeply countersunk lower jaw, flat nose, nasal valves, small and upturned eyes, and a concave belly. The species has 2 color variations, but in Saguaro National Park they are whitish to reddish-orange in color with 19 to 49 black or brown bands. 
Total length: 7 - 11 in (17.8 - 28 cm) 
Diet: centipedes, sand-burrowing cockroaches, ant pupae and other insects

image courtesy of dave prival

Western Groundsnake
(Sonora semiannulata) 
This snake is usually a reddish-brown color, and some are crossbanded with black.  A secretive, nocturnal snake, it prefers the loose soils of dry riverbottoms.  
Total length: 8 - 18 in (20 - 46 cm) 
Diet: Spiders, scorpions, centipedes, crickets, grasshoppers, insect larvae

image courtesy of roy c murray

Western Lyresnake
(Trimorphodon biscutatus) 
This snake is named for the v-shaped lyre on its head.  It lives in rocky areas and wedges itself in crevices and cracks in the rocks.  Lyre snakes are primarily lizard eaters, but they also eat birds and mammals.   They tend to constrict their prey, as their mild venom is not effective on birds and mammals.  When alarmed, this snake will shake its tail, hiss, strike, and bite the offender.  This behavior, as well as the snake’s physical characteristics, often cause the lyre snake to be mistaken for a rattlesnake and killed. 
Total length: 18 - 47 in (46 - 121 cm) 

image courtesy of dave prival

Western Patch-nosed Snake
(Salvadora hexalepis) 
This slender snake has a large scale on the end of its nose, which it uses to burrow in search of food.  It is pale brown, bordered on each side with several dark stripes.  The western patch-nose snake does not constrict its prey, but it does throw loops of its body over the prey, pinning it down until it can be swallowed. 
Total length: 20 - 46 in (51 - 117 cm) 
Diet: Small mammals, lizards, reptile eggs, nestling birds

image courtesy of matt goode

Western Threadsnake
(Leptotyphlops humilis) 
This small, worm-like snake may reach up to 16 inches in length, but it’s rarely thicker than a pencil.  It prefers loose, damp soils and spends so much time underground that its eyes have become vestigial (unneeded) and located under the head scales! When foraging for prey, the blind snake will search an ant pheromone trail and follow it back to the nest for a meal. Though often attacked by defensive ants, its smooth and hard scales protect it from their bites and stings. 
Total length: 7 - 16 in (18 - 41 cm)