Graham's crayfish snake (Regina grahamii)
The Graham's crayfish snake is a non-venomous snake in the family Colubridae. GBIF holds 603 licensed U.S. records of it; it reaches our listing threshold in 10 states, most of all Texas (197), Kansas (161) and Oklahoma (123). Its observation records peak in May.
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Regina grahamii, commonly known as Graham's Crayfish Snake, is a species of nonvenomous semiaquatic snake in the subfamily Natricinae of the family Colubridae. The species is endemic to the central United States.
From Wikipedia: Regina grahamii, text under CC BY-SA 4.0.
Is the Graham's crayfish snake poisonous or venomous?
No. The Graham's crayfish 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 Graham's crayfish snake?
Records are spread over 10 states; the top three, Texas, Kansas and Oklahoma, hold 80% of them.
| # | State | Records | Share of state snakes | Rank in state |
|---|---|---|---|---|
| 1 | Texas | 197 | 0.5% | 44th of 86 |
| 2 | Kansas | 161 | 1.1% | 29th of 44 |
| 3 | Oklahoma | 123 | 0.9% | 26th of 50 |
| 4 | Louisiana | 41 | 0.8% | 20th of 41 |
| 5 | Missouri | 22 | 1.2% | 23rd of 36 |
| 6 | Illinois | 19 | 0.7% | 26th of 33 |
| 7 | Iowa | 19 | 1.8% | 14th of 22 |
| 8 | Nebraska | 10 | 0.4% | 28th of 31 |
| 9 | Mississippi | 5 | 0.3% | 36th of 38 |
| 10 | Arkansas | 4 | 0.1% | 33rd of 36 |
When is the Graham's crayfish snake seen?
Across the U.S., observation records of the Graham's crayfish snake run mostly February through October, peaking in May with 24% of them. Winter (December to February) holds 9% of them.
Where the Graham's crayfish snake is recorded in each state
Texas
Texas holds 197 licensed records, the 44th most recorded of 86 snakes listed there. Most of its licensed records in Texas come from McLennan County, Brazos County and Brazoria County. Next come Bexar County (20) and Chambers County (16).
Kansas
Kansas holds 161 licensed records, the 29th most recorded of 44 snakes listed there. Most of its licensed records in Kansas come from Douglas County, Barton County and Woodson County. Next come Lyon County (7) and Osage County (7).
Oklahoma
Oklahoma holds 123 licensed records, the 26th most recorded of 50 snakes listed there. Most of its licensed records in Oklahoma come from Okmulgee County, Cleveland County and McCurtain County. Next come Comanche County (10) and Tillman County (8).
Louisiana
Louisiana holds 41 licensed records, the joint 20th most recorded of 41 snakes listed there. Most of its licensed records in Louisiana come from Jefferson Parish, Saint Charles Parish and Avoyelles Parish. Next come East Baton Rouge Parish (3) and Saint James Parish (3).
Top counties in the U.S.
| # | County | State | Records | Share of U.S. |
|---|---|---|---|---|
| 1 | Douglas County | Kansas | 37 | 6.1% |
| 2 | Okmulgee County | Oklahoma | 30 | 5.0% |
| 3 | McLennan County | Texas | 25 | 4.1% |
| 4 | Barton County | Kansas | 23 | 3.8% |
| 5 | Brazos County | Texas | 22 | 3.6% |
| 6 | Brazoria County | Texas | 21 | 3.5% |
| 7 | Bexar County | Texas | 20 | 3.3% |
| 8 | Woodson County | Kansas | 18 | 3.0% |
| 9 | Chambers County | Texas | 16 | 2.7% |
| 10 | Cleveland County | Oklahoma | 15 | 2.5% |
| 11 | Wichita County | Texas | 15 | 2.5% |
| 12 | McCurtain County | Oklahoma | 14 | 2.3% |
| 13 | Comanche County | Oklahoma | 10 | 1.7% |
| 14 | Harris County | Texas | 9 | 1.5% |
| 15 | Tillman County | Oklahoma | 8 | 1.3% |
How recent are the Graham's crayfish snake records?
The Graham's crayfish snake record leans on older material: only 16% of dated U.S. records come from 2017–2026, and the median record is from 1964. The oldest dated record is from 1884; the busiest year was 1928, with 24 records.
| Decade | Records | Share |
|---|---|---|
| 1880s | 1 | 0.2% |
| 1900s | 6 | 1.1% |
| 1910s | 12 | 2.2% |
| 1920s | 83 | 15.1% |
| 1930s | 53 | 9.6% |
| 1940s | 36 | 6.5% |
| 1950s | 47 | 8.5% |
| 1960s | 69 | 12.5% |
| 1970s | 50 | 9.1% |
| 1980s | 38 | 6.9% |
| 1990s | 11 | 2.0% |
| 2000s | 31 | 5.6% |
| 2010s | 51 | 9.3% |
| 2020s | 62 | 11.3% |
Species recorded in the same counties
Of the 60 counties where the Graham's crayfish snake is most recorded, 35 are also top counties for the speckled kingsnake, more than for any other snake. None of its closest neighbors is venomous.
| Species | Shared counties |
|---|---|
| Speckled kingsnake | 35 |
| Diamondback water snake | 32 |
| Plain-bellied watersnake | 26 |
| Western rat snake | 25 |
| Common garter snake | 22 |
| Eastern racer | 22 |
| Prairie kingsnake | 22 |
| DeKay's brown snake | 21 |
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.