View endemic snakes in other US states
Common snakes found in the state of Illinois
Copperhead
High Risk
Venomous
50–95 cm (20–37 in)
- Alabama
- Arkansas
- Connecticut
- Delaware
- Florida
- Georgia
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maryland
- Massachusetts
- Mississippi
- Missouri
- Nebraska
- New Jersey
- New York
- North Carolina
- Ohio
- Oklahoma
- Pennsylvania
- South Carolina
- Tennessee
- Texas
- Virginia
- West Virginia
Cottonmouth
High Risk
Venomous
65 to 90 cm (26 to 35 in)
- Alabama
- Arkansas
- Florida
- Georgia
- Illinois
- Indiana
- Kentucky
- Louisiana
- Mississippi
- Missouri
- North Carolina
- Oklahoma
- South Carolina
- Tennessee
- Texas
- Virginia
Timber Rattlesnake
High Risk
Venomous
91–152 cm (36–60 in)
- Alabama
- Arkansas
- Connecticut
- Delaware
- Florida
- Georgia
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maryland
- Massachusetts
- Mississippi
- Missouri
- New Jersey
- New York
- North Carolina
- Ohio
- Oklahoma
- Pennsylvania
- South Carolina
- Tennessee
- Texas
- Virginia
- West Virginia
- Wisconsin
Massasauga
High Risk
Venomous
50–95 cm (20–37 in)
- Arizona
- Illinois
- Indiana
- Iowa
- Minnesota
- Missouri
- New York
- Ohio
- Pennsylvania
- Wisconsin
- Michigan
Scarlet Snake
Low Risk
Nonvenomous
14-26 inches (36–66 cm)
- Alabama
- Arkansas
- Connecticut
- Delaware
- Florida
- Georgia
- Illinois
- Indiana
- Kentucky
- Louisiana
- Maryland
- Massachusetts
- Mississippi
- Missouri
- New Jersey
- New York
- North Carolina
- Oklahoma
- Pennsylvania
- South Carolina
- Tennessee
- Texas
- Virginia
- West Virginia
Kirtland’s Snake
Low Risk
Nonvenomous
30–46 cm (12-18 inches).
- Illinois
- Indiana
- Kentucky
- Michigan
- Ohio
- Pennsylvania
Racer
Low Risk
Nonvenomous
50 -152 cm (20 -60 in)
- All States except Alaska & Hawaii
Ringneck Snake
Zero Risk
Nonvenomous
25–38 cm (10–15 in)
- All States except Alaska & Hawaii
Fox Snake
Low Risk
Nonvenomous
91-182 cm (3 – 6 ft)
- Illinois
- Indiana
- Michigan
- Missouri
- Ohio
- Wisconsin
Mud Snake
Low Risk
Nonvenomous
101.6–137 cm (40–54 in)
- Alabama
- Arkansas
- Florida
- Georgia
- Illinois
- Kentucky
- Louisiana
- Mississippi
- Missouri
- North Carolina
- Oklahoma
- South Carolina
- Tennessee
- Texas
- Virginia
Western Hognose Snake
Low Risk
Nonvenomous
40–50 cm (15–20 in)
- All States except Alaska & Hawaii
Eastern Hognose Snake
Low Risk
Venomous
71 cm (28 in)
- Alabama
- Arkansas
- Connecticut
- Delaware
- Florida
- Georgia
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Minnesota
- Mississippi
- New Hampshire
- New Jersey
- North Carolina
- Pennsylvania
- Rhode Island
- South Carolina
- Tennessee
- Texas
- Virginia
- West Virginia
- Wisconsin
Prairie Kingsnake
Low Risk
Nonvenomous
76–102 cm (30–40 in)
- Alabama
- Arkansas
- Florida
- Georgia
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Michigan
- Minnesota
- Mississippi
- Missouri
- Nebraska
- North Carolina
- North Dakota
- Ohio
- South Carolina
- South Dakota
- Tennessee
- Wisconsin
Common Kingsnake
Low Risk
Nonvenomous
90– 122 cm (35–48 in)
- Alabama
- Arizona
- Arkansas
- California
- Colorado
- Delaware
- Florida
- Georgia
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maryland
- Mississippi
- Missouri
- Nebraska
- Nevada
- NewJersey
- NewMexico
- NewYork
- NorthCarolina
- Ohio
- Oklahoma
- Oregon
- SouthCarolina
- Tennessee
- Texas
- Utah
- Virginia
- WestVirginia
Mississippi Green Water Snake
Low Risk
Nonvenomous
50–95 cm (20–37 in)
- Alabama
- Arkansas
- Florida
- Illinois
- Indiana
- Kentucky
- Louisiana
- Mississippi
- Missouri
- Tennessee
- Texas
Diamondback Water Snake
Low Risk
Nonvenomous
76–122 cm (30–48 in)
- Alabama
- Arkansas
- Georgia
- Illinois
- Indiana
- Iowa
- Kansas
- Louisiana
- Mississippi
- Missouri
- Oklahoma
- Tennessee
- Texas
Northwestern Garter Snake
Low Risk
Nonvenomous
33–97cm (13–38 in)
- California
- Oregon
Smooth Green Snake
Low Risk
Nonvenomous
36–51 cm (14–20 in)
- Colorado
- Illinois
- Illinois
- Indiana
- Iowa
- Kentucky
- Michigan
- Minnesota
- Missouri
- New Mexico
- Ohio
- Texas
- Virginia
- West Virginia
- Wisconsin
- Wyoming
Gopher Snake
Low Risk
Nonvenomous
91–213 cm (36-84 in)
- Arizona
- California
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Missouri
- Montana
- Nebraska
- Nevada
- New Mexico
- North Dakota
- Ohio
- Oklahoma
- Oregon
- South Dakota
- Texas
- Utah
- Washington
- Wisconsin
- Wyoming
Graham’s Crayfish Snake
Low Risk
Nonvenomous
46–71 cm (18–28 in)
- Arkansas
- Illinois
- Iowa
- Kansas
- Louisiana
- Mississippi
- Missouri
- Nebraska
- Oklahoma
- Texas
Queen Snake
Low Risk
Nonvenomous
17–23 cm (7–9 in)
- Alabama
- Connecticut
- Delaware
- Florida
- Georgia
- Illinois
- Indiana
- Kentucky
- Maine
- Maryland
- Massachusetts
- Michigan
- Mississippi
- New Hampshire
- New Jersey
- New York
- North Carolina
- Ohio
- Pennsylvania
- Rhode Island
- South Carolina
- Tennessee
- Vermont
- Virginia
- West Virginia
- Wisconsin
Redbelly Snake
Low Risk
Nonvenomous
4–10 cm (10–25 in)
- All States except Alaska & Hawaii
Flathead Snake
Low Risk
Nonvenomous
18–20 cm (7–8 in)
- Arkansas
- Illinois
- Kansas
- Louisiana
- Missouri
- Oklahoma
- Texas
Plains Garter Snake
Low Risk
Nonvenomous
38–71 cm (15–28 in)
- Alabama
- Arkansas
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Michigan
- Minnesota
- Mississippi
- Missouri
- Nebraska
- North Dakota
- Ohio
- Oklahoma
- South Dakota
- Tennessee
- Texas
- West Virginia
- Wisconsin
Eastern Ribbon Snake
Low Risk
Nonvenomous
41–89 cm (16–35 in)
- Alabama
- Connecticut
- Delaware
- Florida
- Georgia
- Illinois
- Indiana
- Kentucky
- Maine
- Maryland
- Massachusetts
- Michigan
- Mississippi
- New Hampshire
- New Jersey
- New York
- North Carolina
- Ohio
- Pennsylvania
- Rhode Island
- South Carolina
- Tennessee
- Vermont
- Virginia
- West Virginia
- Wisconsin
Common Garter Snake
Low Risk
Nonvenomous
55–137 cm (22–54 in)
- All States except Alaska & Hawaii
Lined Snake
Low Risk
Nonvenomous
50–95 cm (20–37 in)
- Alabama
- Arkansas
- Illinois
- Iowa
- Kansas
- Kentucky
- Louisiana
- Mississippi
- Missouri
- Nebraska
- Oklahoma
- Tennessee
- Texas
Rough Earth Snake
Low Risk
Nonvenomous
18–25 cm (7–10 in)
- Alabama
- Arkansas
- Florida
- Georgia
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Mississippi
- Missouri
- North Carolina
- Oklahoma
- South Carolina
- Tennessee
- Texas
- Virginia
- West Virginia
Smooth Earth Snake
Low Risk
Nonvenomous
18–25 cm (7–10 in)
- Alabama
- Arkansas
- Delaware
- Florida
- Georgia
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maryland
- Mississippi
- Missouri
- Nebraska
- New Jersey
- North Carolina
- Ohio
- Oklahoma
- Pennsylvania
- South Carolina
- Tennessee
- Texas
- Virginia
- West Virginia
For a full list of every venomous and nonvenomous snake found in the USA, check out my full article: Identity 130+ Snake Species From The USA (With Images)