Discover Maryland's Herps

Field Guide to Maryland's Snakes (Order Squamata)

Sub-order Serpentes, Family Colubridae

Northern Watersnake
Nerodia s. sipedon

Northern Watersnake Adult photo by Scott A. Smith
Photo of Adult Northern Watersnake courtesy of  Scott A. Smith


24 - 42 inches. Record - 55⅛ inches.


  • A highly variable species, but typically heavy-bodied with a large rounded head.

  • Often mistaken for “water moccasins” which do not occur in Maryland.

  • They have a back pattern of black to reddish-brown blotches which may form crossbands.

  • Older individuals may appear one dark color, but close examination should reveal some blotches.

  • Reddish-brown to orange-brown “half-moons” on a creamy yellow to pink belly.

  • Keeled scales.

  • Young are strongly patterned black on a pale gray or light brown background.

  • Northern Watersnake Close-up, photo by John White
    Close-up Photo of Northern Watersnake
    courtesy of  John White


    Can be found in or near every type of wetland habitat, from rivers to lakes, and bogs to ponds. Even lives in brackish marshes.

    How to Find

    Walk along wetland edges, particularly where there is slow-moving water. Look for basking individuals near escape cover. Warning: water snakes have a reputation for being ill humored. They will readily bite and “musk” upon handling. Non-venomous.


    Northern Watersnake Habitat, photo by Tony Procheska
    Photo of Northern Watersnake Habitat
    courtesy of Tony Procheska

    Distribution in Maryland

    This snake is found commonly throughout Maryland.


    Maryland Distribution Map for Northern Watersnake

    FaceBook Icon

    Maryland Amphibian
    and Reptile Atlas Project

    "A Joint Project of the Natural History Society of Maryland, Inc. and the Maryland Department of Natural Resources"

    For monthly newsletters of the Maryland Amphibian & Reptile Atlas Project click on Recent Newsletters and scroll down to the MARA Newsletters.

    The Maryland Herpetology Field Guide is a cooperative effort of the MD Natural Heritage Program and the MD Biological Stream Survey within the Department of Natural Resources and their partners. We wish to thank all who contributed field records, text, and photographs, as well as support throughout its development.