Western ribbon snake (Thamnophis proximus)
The western ribbon snake is a snake in the family Colubridae with a mild venom for its prey, not dangerous to people. GBIF holds 4,347 licensed U.S. records of it; it reaches our listing threshold in 13 states, most of all Texas (2,587), Oklahoma (589) and Louisiana (580). Its observation records peak in April.
Thamnophis proximus, commonly known as the western ribbon snake or western ribbonsnake, is a species of garter snake in the subfamily Natricinae of the family Colubridae. The species is found in the central and southern United States, Mexico, and Central America south to central Costa Rica. The species has six recognized subspecies.
From Wikipedia: Thamnophis proximus, text under CC BY-SA 4.0.
Is the western ribbon snake poisonous or venomous?
Mildly venomous but not dangerous: the western ribbon snake has enlarged rear teeth and a mild venom for its prey, and a bite causes at most local swelling, which is why many sources simply call it harmless. It is not a pit viper or coral snake, the only U.S. land snakes with medically dangerous venom. Clean any bite like a small wound.
Which states have the western ribbon snake?
The western ribbon snake's U.S. record is concentrated: Texas alone holds 60% of licensed records. It is listed in 13 states in all; the next are Oklahoma (589), Louisiana (580) and Kansas (302).
| # | State | Records | Share of state snakes | Rank in state |
|---|---|---|---|---|
| 1 | Texas | 2,587 | 6.3% | 2nd of 86 |
| 2 | Oklahoma | 589 | 4.4% | 5th of 50 |
| 3 | Louisiana | 580 | 11.5% | 2nd of 41 |
| 4 | Kansas | 302 | 2.0% | 15th of 44 |
| 5 | Arkansas | 95 | 1.8% | 12th of 36 |
| 6 | Missouri | 60 | 3.2% | 10th of 36 |
| 7 | Illinois | 50 | 1.8% | 17th of 33 |
| 8 | Tennessee | 24 | 0.9% | 21st of 32 |
| 9 | Mississippi | 14 | 0.8% | 29th of 38 |
| 10 | New Mexico | 14 | 0.2% | 41st of 56 |
| 11 | Iowa | 9 | 0.9% | 20th of 22 |
| 12 | Indiana | 8 | 0.4% | 27th of 27 |
| 13 | Nebraska | 7 | 0.3% | 30th of 31 |
When is the western ribbon snake seen?
Across the U.S., observation records of the western ribbon snake run mostly March through November, peaking in April with 20% of them. Winter (December to February) holds 9% of them.
Season by state
Observation records run through most of the year in Louisiana. Among states whose main season falls within one calendar year, it starts earliest in March (Arkansas, Missouri and Texas) and latest in April (Oklahoma). The most common peak month is April, shared by Louisiana and Texas.
| State | Main season | Peak month | Observation records |
|---|---|---|---|
| Texas | March through November | April | 877 |
| Louisiana | most of the year | April | 255 |
| Arkansas | March through October | June | 70 |
| Oklahoma | April through October | September | 68 |
| Missouri | March through October | March | 32 |
Where the western ribbon snake is recorded in each state
Texas
Texas holds 2,587 licensed records, the 2nd most recorded of 86 snakes listed there. Its observation records in Texas run mostly March through November, peaking in April; most licensed records come from Travis County, Harris County and Cameron County. Next come Brazoria County (68) and Val Verde County (65).
Oklahoma
Oklahoma holds 589 licensed records, the 5th most recorded of 50 snakes listed there. Its observation records in Oklahoma run mostly April through October, peaking in September; most licensed records come from Comanche County, Cleveland County and Woodward County. Next come McCurtain County (41) and Woods County (25).
Louisiana
Louisiana holds 580 licensed records, the 2nd most recorded of 41 snakes listed there. Its observation records in Louisiana run through most of the year, peaking in April; most licensed records come from East Baton Rouge Parish, Saint Bernard Parish and Jefferson Parish. Next come Saint Tammany Parish (34) and Plaquemines Parish (32).
Kansas
Kansas holds 302 licensed records, the 15th most recorded of 44 snakes listed there. Most of its licensed records in Kansas come from Cherokee County, Edwards County and Meade County. Next come Ellis County (23) and Douglas County (17).
Arkansas
Arkansas holds 95 licensed records, the 12th most recorded of 36 snakes listed there. Its observation records in Arkansas run mostly March through October, peaking in June; most licensed records come from Washington County, Clay County and Columbia County. Next come Greene County (6) and Sebastian County (6).
Missouri
Missouri holds 60 licensed records, the 10th most recorded of 36 snakes listed there. Its observation records in Missouri run mostly March through October, peaking in March; most licensed records come from Linn County, Lewis County and Cape Girardeau County. Next come Miller County (4) and New Madrid County (4).
Illinois
Illinois holds 50 licensed records, the 17th most recorded of 33 snakes listed there. Most of its licensed records in Illinois come from Union County, St. Clair County and Jackson County. Next come Wabash County (4) and Richland County (3).
Top counties in the U.S.
| # | County | State | Records | Share of U.S. |
|---|---|---|---|---|
| 1 | Travis County | Texas | 196 | 4.5% |
| 2 | Harris County | Texas | 175 | 4.0% |
| 3 | Comanche County | Oklahoma | 110 | 2.5% |
| 4 | East Baton Rouge Parish | Louisiana | 107 | 2.5% |
| 5 | Cameron County | Texas | 75 | 1.7% |
| 6 | Cleveland County | Oklahoma | 71 | 1.6% |
| 7 | Brazoria County | Texas | 68 | 1.6% |
| 8 | Val Verde County | Texas | 65 | 1.5% |
| 9 | Saint Bernard Parish | Louisiana | 61 | 1.4% |
| 10 | Hutchinson County | Texas | 55 | 1.3% |
| 11 | Uvalde County | Texas | 55 | 1.3% |
| 12 | Brazos County | Texas | 54 | 1.2% |
| 13 | Hidalgo County | Texas | 53 | 1.2% |
| 14 | Jefferson Parish | Louisiana | 50 | 1.2% |
| 15 | Woodward County | Oklahoma | 47 | 1.1% |
How recent are the western ribbon snake records?
The western ribbon snake record leans on older material: only 33% of dated U.S. records come from 2017–2026, and the median record is from 1991. The oldest dated record is from 1853; the busiest year was 2023, with 168 records.
| Decade | Records | Share |
|---|---|---|
| 1850s | 1 | 0.0% |
| 1870s | 1 | 0.0% |
| 1880s | 7 | 0.2% |
| 1890s | 15 | 0.4% |
| 1900s | 45 | 1.1% |
| 1910s | 30 | 0.7% |
| 1920s | 119 | 3.0% |
| 1930s | 203 | 5.1% |
| 1940s | 215 | 5.4% |
| 1950s | 400 | 10.0% |
| 1960s | 419 | 10.4% |
| 1970s | 386 | 9.6% |
| 1980s | 142 | 3.5% |
| 1990s | 120 | 3.0% |
| 2000s | 348 | 8.7% |
| 2010s | 539 | 13.4% |
| 2020s | 1,020 | 25.4% |
Species recorded in the same counties
Of the 80 counties where the western ribbon snake is most recorded, 41 are also top counties for the plain-bellied watersnake, more than for any other snake. None of its closest neighbors is venomous.
| Species | Shared counties |
|---|---|
| Plain-bellied watersnake | 41 |
| DeKay's brown snake | 39 |
| Diamondback water snake | 37 |
| Eastern racer | 36 |
| Western rat snake | 34 |
| Rough greensnake | 33 |
| Speckled kingsnake | 33 |
| Common garter snake | 30 |
Related species in the U.S.
Other species of the genus Thamnophis with profiles here: Western terrestrial garter snake, Common garter snake, Aquatic garter snake, Northwestern garter snake, Western aquatic garter snake, Plains garter snake, Checkered garter snake and Eastern ribbonsnake.
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.