MARYLAND - As Marylanders flock to the trails of Catoctin Mountain Park and the C&O Canal Towpath this season, the state's reptile residents are waking up. While the Old Line State is home to 27 species of snakes, hikers can breathe a sigh of relief: only two are venomous.
However, recent seasonal warnings from the Maryland Department of Natural Resources regarding juvenile copperheads highlight a critical reality: just because they are rare doesn't mean they aren't there. Misidentification is common, with many harmless water snakes falling victim to the shovel because they were mistaken for "water moccasins."
Here is the definitive guide to the only two venomous snakes you actually need to worry about in Maryland.
1. The Copperhead (Agkistrodon contortrix)
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Danger Level: Moderate (Responsible for the vast majority of venomous bites in MD)
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Where they hide: Statewide. Common in the rocky, wooded hills of the Piedmont (like Sugarloaf Mountain) and Western Maryland, but also present in the Coastal Plain.
The Copperhead is the snake you are most likely to encounter. They are masters of camouflage, blending perfectly into dead oak leaves and underbrush. Unlike many snakes that flee when they feel vibration, Copperheads often freeze in place, relying on their disguise. This makes them easy to step on accidentally.
- ID Tip: Look for the "Hershey’s Kiss" pattern—dark brown hourglass or saddlebag shapes on a tan or coppery body.
- Seasonal Note: In late summer and fall, keep an eye out for juvenile copperheads. They are tiny (8–10 inches) and have a bright yellow or green tip on their tail, which they wiggle to lure prey.
2. The Timber Rattlesnake (Crotalus horridus)
- Danger Level: Very High
- Where they hide: Western Maryland only. Primarily found in Frederick, Washington, Allegany, and Garrett counties.
The Timber Rattlesnake is the heavyweight of the Maryland mountains. They are generally shy and reclusive, preferring the deep solitude of rocky ridges and dense forests in areas like Cunningham Falls or Green Ridge State Forest. In Maryland, these snakes appear in two distinct color "phases":
- Yellow Phase: Yellow/brown body with dark V-shaped chevrons.
- Black Phase: Almost entirely black with a dark head (often harder to spot).
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ID Tip: A heavy body, a broad triangular head, and a distinct rattle at the end of a black tail.
The Myth: The Cottonmouth / Water Moccasin
Let’s settle the debate once and for all: There are no Cottonmouths in Maryland.
The northern limit of the Cottonmouth's range is in southern Virginia.
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What you are seeing: If you see a thick, dark snake swimming in the Patapsco River, Loch Raven Reservoir, or the Chesapeake Bay, it is almost certainly a Northern Watersnake. These snakes are non-venomous but aggressive; they will flatten their heads when cornered to mimic a venomous viper, but they are harmless.
Safety & First Aid
In Maryland, snakes are considered wildlife and are protected by law. It is illegal to kill them.
If You Are Bitten:
- Call 911 immediately.
- Stay Calm. Panic increases heart rate and spreads venom faster.
- Remove Constriction. Take off rings, watches, and tight boots immediately. Swelling will be rapid.
- Do NOT use a tourniquet, cut the wound, or apply ice.
Most bites occur when people try to handle or kill a snake. The best policy is always to give them space and let them pass.
Maryland DNR: Venomous Snake Identification Guide This video from local wildlife experts explains why Copperheads are so active in the fall and how to spot them before you step on
