Western ground snake (Sonora semiannulata)
The western ground snake is a non-venomous snake in the family Colubridae. GBIF holds 4,704 licensed U.S. records of it; it reaches our listing threshold in 10 states, most of all Texas (1,963), Oklahoma (1,354) and Arizona (638). Its observation records peak in May.

The western ground snake (Sonora semiannulata) is a species of small, harmless colubrid snake. The species is endemic to North America. Its patterning and coloration can vary widely, even within the same geographic region.
From Wikipedia: Western ground snake, text under CC BY-SA 4.0.
Is the western ground snake poisonous or venomous?
No. The western ground snake is non-venomous: it belongs to the family Colubridae, not to the pit vipers or coral snakes, the only U.S. land snakes with medically dangerous venom. It may bite if handled; clean the bite like any small wound.
Which states have the western ground snake?
Records are spread over 10 states; the top three, Texas, Oklahoma and Arizona, hold 84% of them. It is the most recorded snake of all in Oklahoma.
| # | State | Records | Share of state snakes | Rank in state |
|---|---|---|---|---|
| 1 | Texas | 1,963 | 4.8% | 5th of 86 |
| 2 | Oklahoma | 1,354 | 10.2% | 1st of 50 |
| 3 | Arizona | 638 | 3.1% | 11th of 60 |
| 4 | California | 296 | 0.4% | 26th of 46 |
| 5 | Kansas | 266 | 1.8% | 16th of 44 |
| 6 | Nevada | 83 | 2.1% | 15th of 27 |
| 7 | Colorado | 36 | 1.0% | 11th of 26 |
| 8 | New Mexico | 34 | 0.5% | 29th of 56 |
| 9 | Utah | 27 | 0.8% | 12th of 28 |
| 10 | Idaho | 6 | 0.4% | 9th of 11 |
When is the western ground snake seen?
Across the U.S., observation records of the western ground snake run mostly March through August, peaking in May with 42% of them. Almost none are from December to February.
Where the western ground snake is recorded in each state
Texas
Texas holds 1,963 licensed records, the 5th most recorded of 86 snakes listed there. Most of its licensed records in Texas come from Palo Pinto County, Burnet County and Archer County. Next come Crockett County (90) and Shackelford County (68).
Oklahoma
Oklahoma holds 1,354 licensed records, the most recorded of 50 snakes listed there. Most of its licensed records in Oklahoma come from Tulsa County, Osage County and Beckham County. Next come Comanche County (89) and Payne County (77).
Arizona
Arizona holds 638 licensed records, the 11th most recorded of 60 snakes listed there. Its observation records in Arizona run mostly March through August, peaking in May; most licensed records come from Maricopa County, Yuma County and Pima County. Next come Santa Cruz County (43) and Yavapai County (41).
California
California holds 296 licensed records, the 26th most recorded of 46 snakes listed there. Most of its licensed records in California come from Imperial County, Inyo County and San Bernardino County. Next come Kern County (2) and Los Angeles County (1).
Kansas
Kansas holds 266 licensed records, the 16th most recorded of 44 snakes listed there. Most of its licensed records in Kansas come from Cowley County, Clark County and Barber County. Next come Russell County (17) and Chautauqua County (15).
Nevada
Nevada holds 83 licensed records, the 15th most recorded of 27 snakes listed there. Most of its licensed records in Nevada come from Clark County, Nye County and Washoe County. Next come Churchill County (5) and Mineral County (4).
Colorado
Colorado holds 36 licensed records, the 11th most recorded of 26 snakes listed there. Most of its licensed records in Colorado come from Otero County, Las Animas County and Baca County.
New Mexico
New Mexico holds 34 licensed records, the joint 29th most recorded of 56 snakes listed there. Most of its licensed records in New Mexico come from Doña Ana County, Sierra County and Hidalgo County. Next come Eddy County (4) and Grant County (2).
Top counties in the U.S.
| # | County | State | Records | Share of U.S. |
|---|---|---|---|---|
| 1 | Tulsa County | Oklahoma | 535 | 11.4% |
| 2 | Palo Pinto County | Texas | 348 | 7.4% |
| 3 | Maricopa County | Arizona | 343 | 7.3% |
| 4 | Imperial County | California | 245 | 5.2% |
| 5 | Burnet County | Texas | 134 | 2.8% |
| 6 | Archer County | Texas | 117 | 2.5% |
| 7 | Osage County | Oklahoma | 109 | 2.3% |
| 8 | Cowley County | Kansas | 95 | 2.0% |
| 9 | Beckham County | Oklahoma | 91 | 1.9% |
| 10 | Crockett County | Texas | 90 | 1.9% |
| 11 | Comanche County | Oklahoma | 89 | 1.9% |
| 12 | Payne County | Oklahoma | 77 | 1.6% |
| 13 | Shackelford County | Texas | 68 | 1.4% |
| 14 | Wichita County | Texas | 61 | 1.3% |
| 15 | Brewster County | Texas | 60 | 1.3% |
How recent are the western ground snake records?
The western ground snake record leans on older material: only 2% of dated U.S. records come from 2017–2026, and the median record is from 1951. The oldest dated record is from 1885; the busiest year was 1935, with 276 records.
| Decade | Records | Share |
|---|---|---|
| 1880s | 2 | 0.0% |
| 1890s | 3 | 0.1% |
| 1900s | 17 | 0.4% |
| 1910s | 39 | 0.9% |
| 1920s | 63 | 1.5% |
| 1930s | 1,043 | 24.4% |
| 1940s | 837 | 19.6% |
| 1950s | 677 | 15.9% |
| 1960s | 477 | 11.2% |
| 1970s | 354 | 8.3% |
| 1980s | 195 | 4.6% |
| 1990s | 162 | 3.8% |
| 2000s | 151 | 3.5% |
| 2010s | 193 | 4.5% |
| 2020s | 55 | 1.3% |
Species recorded in the same counties
Of the 87 counties where the western ground snake is most recorded, 65 are also top counties for the gopher snake, more than for any other snake. Venomous species among its neighbors: the western diamondback rattlesnake.
| Species | Shared counties |
|---|---|
| Gopher snake | 65 |
| Coachwhip | 56 |
| Long-nosed snake | 45 |
| Ring-necked snake | 42 |
| Glossy snake | 39 |
| Striped whipsnake | 36 |
| Plains black-headed snake | 34 |
| Western diamondback rattlesnake venomous | 31 |
Related species in the U.S.
Other members of the family Colubridae with profiles here: Western terrestrial garter snake, Common garter snake, Gopher snake, Ring-necked snake, Northern water snake and Eastern racer.
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.