Trans-Pecos rat snake (Bogertophis subocularis)
The Trans-Pecos rat snake is a non-venomous snake in the family Colubridae. GBIF holds 414 licensed U.S. records of it; it reaches our listing threshold in 2 states, most of all Texas (373) and New Mexico (40). Its observation records peak in June.
The Trans-Pecos rat snake or Davis Mountain rat snake (Bogertophis subocularis), is a species of medium to large, nonvenomous rat snake in the family Colubridae. Bogertophis subocularis is endemic to the Chihuahuan Desert.
From Wikipedia: Trans-Pecos rat snake, text under CC BY-SA 4.0.
Is the Trans-Pecos rat snake poisonous or venomous?
No. The Trans-Pecos rat 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 Trans-Pecos rat snake?
The Trans-Pecos rat snake's U.S. record is concentrated: Texas alone holds 90% of licensed records. It is listed in 2 states in all; the next are New Mexico (40).
| # | State | Records | Share of state snakes | Rank in state |
|---|---|---|---|---|
| 1 | Texas | 373 | 0.9% | 32nd of 86 |
| 2 | New Mexico | 40 | 0.6% | 26th of 56 |
When is the Trans-Pecos rat snake seen?
Across the U.S., observation records of the Trans-Pecos rat snake run mostly April through August, peaking in June with 33% of them. Winter (December to February) holds 2% of them.
Where the Trans-Pecos rat snake is recorded in each state
Texas
Texas holds 373 licensed records, the 32nd most recorded of 86 snakes listed there. Its observation records in Texas run mostly April through August, peaking in June; most licensed records come from El Paso County, Brewster County and Val Verde County. Next come Hudspeth County (32) and Terrell County (25).
New Mexico
New Mexico holds 40 licensed records, the 26th most recorded of 56 snakes listed there. Most of its licensed records in New Mexico come from Eddy County, Doña Ana County and Sierra County. Next come Otero County (2) and Hidalgo County (1).
Top counties in the U.S.
| # | County | State | Records | Share of U.S. |
|---|---|---|---|---|
| 1 | El Paso County | Texas | 94 | 22.7% |
| 2 | Brewster County | Texas | 90 | 21.7% |
| 3 | Val Verde County | Texas | 40 | 9.7% |
| 4 | Hudspeth County | Texas | 32 | 7.7% |
| 5 | Eddy County | New Mexico | 26 | 6.3% |
| 6 | Terrell County | Texas | 25 | 6.0% |
| 7 | Presidio County | Texas | 24 | 5.8% |
| 8 | Culberson County | Texas | 21 | 5.1% |
| 9 | Jeff Davis County | Texas | 20 | 4.8% |
| 10 | Doña Ana County | New Mexico | 8 | 1.9% |
| 11 | Pecos County | Texas | 7 | 1.7% |
| 12 | Crockett County | Texas | 6 | 1.4% |
| 13 | Reeves County | Texas | 4 | 1.0% |
| 14 | Sierra County | New Mexico | 3 | 0.7% |
| 15 | Edwards County | Texas | 3 | 0.7% |
How recent are the Trans-Pecos rat snake records?
The Trans-Pecos rat snake record leans on older material: only 8% of dated U.S. records come from 2016–2025, and the median record is from 1983. The oldest dated record is from 1916; the busiest year was 2013, with 21 records.
| Decade | Records | Share |
|---|---|---|
| 1910s | 1 | 0.3% |
| 1930s | 3 | 0.8% |
| 1940s | 9 | 2.3% |
| 1950s | 18 | 4.5% |
| 1960s | 75 | 18.8% |
| 1970s | 88 | 22.1% |
| 1980s | 31 | 7.8% |
| 1990s | 47 | 11.8% |
| 2000s | 39 | 9.8% |
| 2010s | 73 | 18.3% |
| 2020s | 15 | 3.8% |
Species recorded in the same counties
Of the 20 counties where the Trans-Pecos rat snake is most recorded, 18 are also top counties for both the Chihuahuan night snake and the gopher snake; no other snake shares more. Venomous species among its neighbors: the eastern black-tailed rattlesnake and the rock rattlesnake.
| Species | Shared counties |
|---|---|
| Chihuahuan night snake | 18 |
| Gopher snake | 18 |
| Eastern black-tailed rattlesnake venomous | 16 |
| Rock rattlesnake venomous | 16 |
| Chihuahuan hook-nosed snake | 14 |
| Long-nosed snake | 14 |
| Striped whipsnake | 14 |
| Eastern patch-nosed snake | 13 |
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.