Missouri is home to a rich and diverse array of wildlife, supporting nearly 50 species of snakes across its varied landscapes, from the dense forests of the Ozarks to the marshy lowlands of the Bootheel. Snakes play a significant role in maintaining the natural balance by controlling rodent and insect populations. Understanding the types of snakes present in the state is the first step toward safe and respectful coexistence. This guide offers clear identification methods and practical advice for navigating Missouri’s outdoors without conflict.
The Critical Distinction: Identifying Venomous vs. Non-Venomous
All five of Missouri’s venomous species belong to the pit viper family, sharing distinct physical characteristics that differentiate them from non-venomous counterparts. Pit vipers possess a deep, heat-sensing pit located on each side of the head, positioned between the eye and the nostril, which non-venomous snakes lack entirely. The most reliable features for identification involve the head and the underside of the tail.
Venomous pit vipers have elliptical pupils that appear as vertical slits, similar to a cat’s eye, while harmless species have distinctly round pupils. The head shape is often described as triangular or spade-shaped in pit vipers. However, some non-venomous snakes, like water snakes and hognose snakes, can flatten their heads to imitate this appearance when threatened.
The pattern of scales on the underside of the tail, known as subcaudal scales, is another distinguishing trait. Venomous snakes have a single row of scales running from the anal plate to the tail tip. Non-venomous snakes, conversely, display a double row of scales along the underside of their tails.
Profiles of Missouri’s Venomous Species
The Eastern Copperhead is the most commonly encountered venomous snake in Missouri and is found throughout the entire state. Its color varies from grayish-brown to a pinkish-tan, featuring distinct reddish-brown crossbands that narrow along the center of the back, creating an hourglass pattern. Adults typically measure between 24 and 36 inches in length, and their camouflage is highly effective in leaf litter and wooded areas.
The Western Cottonmouth, also known as the Water Moccasin, is primarily restricted to the southeastern corner of Missouri and the Ozark Region, often near water sources like swamps and rivers. These heavy-bodied snakes reach 30 to 42 inches, exhibiting a dark pattern that can appear black or dark brown with dark bands. When alarmed, the cottonmouth may display the bright white interior of its mouth, which gives the species its common name.
Missouri’s largest venomous snake is the Timber Rattlesnake, which can grow up to 60 inches long. This species is generally tan or yellowish-tan with dark brown or black markings forming bands near the tail, and it possesses a large, unmistakable rattle. Although found statewide, their populations are often scattered due to habitat fragmentation, and they prefer wooded uplands and rocky bluffs.
The two smaller rattlesnake species in the state are more geographically limited. The Massasauga is very rare, primarily located in northern Missouri, preferring wet, marshy habitats. This medium-sized rattlesnake measures 18 to 30 inches and has a pattern of dark brown or black blotches on a gray or light brown body.
The Western Pygmy Rattlesnake is found in the counties bordering Arkansas and the eastern Ozark region. It is characterized by a grayish-brown body with a dorsal stripe and a series of dark blotches. Its rattle is quite small and produces a faint buzzing sound rather than the loud warning associated with larger rattlesnakes.
The Harmless Majority: Common Non-Venomous Snakes
The vast majority of Missouri’s snakes are non-venomous and are beneficial to the environment, often fulfilling a role as natural pest control. The Western Ratsnake, formerly known as the Black Rat Snake, is an excellent climber frequently found in wooded areas, barns, and attics where it hunts rodents. These snakes can grow quite long, sometimes exceeding four feet, and they can range from solid black to patterned with blotches.
Garter Snakes are among the most common snakes in the state, recognizable by their three yellowish stripes running down their greenish, brown, or black bodies. They are highly adaptable and thrive in a wide variety of habitats, including meadows, woodlands, and grassy areas near water.
The Speckled Kingsnake is a widely distributed species, sometimes called the “salt and pepper snake” for its dark body covered in light, speckled markings. Kingsnakes are particularly important ecologically because they are known to prey on other snakes, including venomous species, as they possess an immunity to the venom of pit vipers.
The Ring-necked Snake is a smaller, more secretive snake, easily identified by its uniform dark color, bright yellow or orange belly, and a distinct yellow ring around its neck. They prefer rocky, wooded hillsides and spend much of their time hidden under rocks and logs.
Safety, Prevention, and Respectful Coexistence
Prevention Around Homes
Preventing snake encounters around human dwellings involves eliminating the cover and food sources that attract them. Removing piles of rocks, boards, scrap metal, and other debris reduces the number of hiding places for both snakes and the rodents they prey upon. Individuals should take care when walking through tall grass, dense brush, or rocky areas where snakes may be resting or hunting.
Encounter Protocol
When a snake is encountered, the most important action is to leave it alone and give it ample space. Snakes are generally shy and only bite when they feel threatened or are accidentally provoked. Attempting to capture, kill, or harass a snake increases the risk of a bite and is typically unnecessary. Most defensive behaviors, like the cottonmouth’s open-mouth display or the rattlesnake’s rattle, are warnings to back away.
If a Bite Occurs
If a bite from a venomous snake occurs, immediate medical attention is necessary, and emergency services should be contacted right away. Keep the bitten person calm and limit movement to slow the spread of venom. Actions such as cutting the wound, attempting to suck out the venom, or applying a tourniquet should be avoided, as they can cause more harm than good.