Rock rattlesnake (Crotalus lepidus)
The rock rattlesnake is a venomous pit viper in the family Viperidae. GBIF holds 507 licensed U.S. records of it; it reaches our listing threshold in 3 states, most of all Texas (255), Arizona (161) and New Mexico (91). Its observation records peak in August.
Crotalus lepidus is a venomous pit viper species found in the southwestern United States and northern central Mexico. Four subspecies are currently recognized, including the nominate subspecies described here.
From Wikipedia: Crotalus lepidus, text under CC BY-SA 4.0.
Is the rock rattlesnake poisonous or venomous?
Yes. The rock rattlesnake is a pit viper (family Viperidae), like every rattlesnake, copperhead and cottonmouth in the U.S. Its bite needs emergency care: call 911 and keep the bitten limb still. Antivenom is given in hospital.
Snakes often mistaken for it
Species commonly confused with rattlesnakes and recorded in the same states: gopher snake (recorded in all 3 of its states), plains hog-nosed snake (recorded in all 3 of its states), Great Plains rat snake (recorded in 2 of its 3 states) and eastern hog-nosed snake (recorded in 1 of its 3 states).
Which states have the rock rattlesnake?
The rock rattlesnake's U.S. record is concentrated: Texas alone holds 50% of licensed records. It is listed in 3 states in all; the next are Arizona (161) and New Mexico (91).
| # | State | Records | Share of state snakes | Rank in state |
|---|---|---|---|---|
| 1 | Texas | 255 | 0.6% | 38th of 86 |
| 2 | Arizona | 161 | 0.8% | 30th of 60 |
| 3 | New Mexico | 91 | 1.4% | 14th of 56 |
When is the rock rattlesnake seen?
Across the U.S., observation records of the rock rattlesnake run mostly May through September, peaking in August with 33% of them. Almost none are from December to February.
Season by state
Among states whose main season falls within one calendar year, it starts earliest in May (Texas) and latest in July (Arizona). Each of these states peaks in a different month: June in Texas and August in Arizona.
| State | Main season | Peak month | Observation records |
|---|---|---|---|
| Arizona | July through September | August | 45 |
| Texas | May through September | June | 32 |
Where the rock rattlesnake is recorded in each state
Texas
Texas holds 255 licensed records, the 38th most recorded of 86 snakes listed there. Its observation records in Texas run mostly May through September, peaking in June; most licensed records come from Jeff Davis County, El Paso County and Terrell County. Next come Val Verde County (34) and Brewster County (28).
Arizona
Arizona holds 161 licensed records, the 30th most recorded of 60 snakes listed there. Its observation records in Arizona run mostly July through September, peaking in August; most licensed records come from Cochise County, Santa Cruz County and Pima County.
New Mexico
New Mexico holds 91 licensed records, the 14th most recorded of 56 snakes listed there. Most of its licensed records in New Mexico come from Doña Ana County, Grant County and Hidalgo County. Next come Socorro County (17) and Luna County (6).
Top counties in the U.S.
| # | County | State | Records | Share of U.S. |
|---|---|---|---|---|
| 1 | Cochise County | Arizona | 131 | 25.8% |
| 2 | Jeff Davis County | Texas | 58 | 11.4% |
| 3 | El Paso County | Texas | 38 | 7.5% |
| 4 | Terrell County | Texas | 35 | 6.9% |
| 5 | Val Verde County | Texas | 34 | 6.7% |
| 6 | Santa Cruz County | Arizona | 28 | 5.5% |
| 7 | Brewster County | Texas | 28 | 5.5% |
| 8 | Doña Ana County | New Mexico | 22 | 4.3% |
| 9 | Grant County | New Mexico | 18 | 3.6% |
| 10 | Hidalgo County | New Mexico | 18 | 3.6% |
| 11 | Socorro County | New Mexico | 17 | 3.4% |
| 12 | Presidio County | Texas | 12 | 2.4% |
| 13 | Hudspeth County | Texas | 9 | 1.8% |
| 14 | Culberson County | Texas | 9 | 1.8% |
| 15 | Real County | Texas | 7 | 1.4% |
How recent are the rock rattlesnake records?
The rock rattlesnake record leans on older material: only 15% of dated U.S. records come from 2017–2026, and the median record is from 1975. The oldest dated record is from 1860; the busiest year was 1949, with 23 records.
| Decade | Records | Share |
|---|---|---|
| 1860s | 1 | 0.2% |
| 1880s | 1 | 0.2% |
| 1890s | 4 | 0.9% |
| 1900s | 6 | 1.3% |
| 1910s | 5 | 1.1% |
| 1920s | 13 | 2.9% |
| 1930s | 37 | 8.2% |
| 1940s | 28 | 6.2% |
| 1950s | 34 | 7.5% |
| 1960s | 60 | 13.2% |
| 1970s | 53 | 11.7% |
| 1980s | 45 | 9.9% |
| 1990s | 29 | 6.4% |
| 2000s | 33 | 7.3% |
| 2010s | 57 | 12.6% |
| 2020s | 47 | 10.4% |
Species recorded in the same counties
Of the 27 counties where the rock rattlesnake is most recorded, 25 are also top counties for the gopher snake, more than for any other snake.
| Species | Shared counties |
|---|---|
| Gopher snake | 25 |
| Chihuahuan hook-nosed snake | 20 |
| Chihuahuan night snake | 20 |
| Eastern black-tailed rattlesnake venomous | 20 |
| Striped whipsnake | 20 |
| Eastern patch-nosed snake | 19 |
| Long-nosed snake | 19 |
| Western diamondback rattlesnake venomous | 19 |
Related species in the U.S.
Other species of the genus Crotalus with profiles here: Western rattlesnake, Western diamondback rattlesnake, Prairie rattlesnake, Sidewinder, Timber rattlesnake, Mohave rattlesnake, Red diamond rattlesnake and Black-tailed rattlesnake.
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.