Snakes in Idaho
Idaho has 11 snake species on record, each with at least 10 GBIF records in the state, and 1,474 licensed records in all. The most recorded are the western terrestrial garter snake, the gopher snake and the western rattlesnake. Two of them are venomous.
Rattlesnakes in Idaho
Rattlesnakes: two species are listed for Idaho, with 258 records (18% of the state's snake records). The most recorded is the western rattlesnake (195), ahead of the prairie rattlesnake (63).
Observation records of the western rattlesnake in Idaho run mostly April through August, peaking in July; most licensed records come from Ada County, Adams County and Elmore County. Most licensed records of the prairie rattlesnake in Idaho come from Lemhi County, Ada County and Butte County.
Garter snakes and ribbon snakes in Idaho
Garter snakes and ribbon snakes dominate the snake record of Idaho: two species and 52% of all records. The most recorded is the western terrestrial garter snake (616), ahead of the common garter snake (151).
Observation records of the western terrestrial garter snake in Idaho run mostly April through October, peaking in June; most licensed records come from Bonneville County, Ada County and Bingham County. Observation records of the common garter snake in Idaho run mostly May through October, peaking in September; most licensed records come from Bannock County, Valley County and Kootenai County.
Racers, whipsnakes and indigo snakes in Idaho
Racers, whipsnakes and indigo snakes: two species are listed for Idaho, with 155 records (11% of the state's snake records). The most recorded is the eastern racer (113), ahead of the striped whipsnake (42).
Observation records of the eastern racer in Idaho run mostly May through September, peaking in May; most licensed records come from Ada County, Bannock County and Owyhee County. Most licensed records of the striped whipsnake in Idaho come from Owyhee County, Ada County and Cassia County.
Gopher snakes, bullsnakes and pine snakes in Idaho
One species of this group is listed for Idaho: the gopher snake, with 204 records (14% of the state's snake records).
Observation records of the gopher snake in Idaho run mostly April through September, peaking in May; most licensed records come from Ada County, Idaho County and Owyhee County.
Small woodland and burrowing snakes in Idaho
Small woodland and burrowing snakes are a small part of the snake record here: three species with 1% of records between them. The most recorded is the western ground snake (6), ahead of the desert nightsnake (5).
Boas and pythons in Idaho
One species of this group is listed for Idaho: the northern rubber boa, with 61 records (4% of the state's snake records).
Most licensed records of the northern rubber boa in Idaho come from Bannock County, Idaho County and Latah County.
Where in Idaho are snakes recorded most?
Ada County leads with 279 records (19%), followed by Bannock County and Owyhee County; the top five counties hold 45% of the total. 42 of Idaho's 44 counties have at least one licensed snake record.
| # | County | Records | Share |
|---|---|---|---|
| 1 | Ada County | 279 | 18.9% |
| 2 | Bannock County | 113 | 7.7% |
| 3 | Owyhee County | 99 | 6.7% |
| 4 | Bonneville County | 98 | 6.6% |
| 5 | Idaho County | 74 | 5.0% |
| 6 | Blaine County | 72 | 4.9% |
| 7 | Valley County | 69 | 4.7% |
| 8 | Bingham County | 66 | 4.5% |
| 9 | Latah County | 53 | 3.6% |
| 10 | Caribou County | 49 | 3.3% |
| 11 | Adams County | 46 | 3.1% |
| 12 | Kootenai County | 41 | 2.8% |
When do snakes come out in Idaho?
Observation records of snakes in Idaho run mostly April through September, peaking in May with 25% of them. December through February together hold under 2% of the records, so snakes in Idaho are rarely recorded in winter. The sharpest rise comes from April to May.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 0% | 0% | 1% | 8% | 25% | 22% | 14% | 9% | 13% | 6% | 0% | 0% |
Snakes: Idaho compared with its neighbors
Idaho ranks 40th of 50 states by the number of snake species listed, level with Washington and Wyoming; Texas leads with 86 species.
Of the six states bordering Idaho, Utah, Nevada and Oregon list more snake species; Washington and Wyoming list as many (Idaho: 11 species; Utah 28, Nevada 27, Oregon 16, Washington 11, Wyoming 11, Montana 9).
What snakes are in Idaho? All 11 species
Ranked by licensed records in Idaho. Species with a profile page are linked.
| # | Species | Family | Records | Share |
|---|---|---|---|---|
| 1 | Western terrestrial garter snake Thamnophis elegans | Colubridae | 616 | 41.8% |
| 2 | Gopher snake Pituophis catenifer | Colubridae | 204 | 13.8% |
| 3 | Western rattlesnake venomous Crotalus oreganus | Viperidae | 195 | 13.2% |
| 4 | Common garter snake Thamnophis sirtalis | Colubridae | 151 | 10.2% |
| 5 | Eastern racer Coluber constrictor | Colubridae | 113 | 7.7% |
| 6 | Prairie rattlesnake venomous Crotalus viridis | Viperidae | 63 | 4.3% |
| 7 | Northern rubber boa Charina bottae | Boidae | 61 | 4.1% |
| 8 | Striped whipsnake Masticophis taeniatus | Colubridae | 42 | 2.8% |
| 9 | Western ground snake Sonora semiannulata | Colubridae | 6 | 0.4% |
| 10 | Desert nightsnake Hypsiglena chlorophaea | Colubridae | 5 | 0.3% |
| 11 | Ring-necked snake Diadophis punctatus | Colubridae | 4 | 0.3% |
Also recorded in Idaho, fewer than 10 times
Beyond the main list, two snake species are known from Idaho by only 3 to 9 records each. Some are genuine rarities at the edge of their range; others may be strays, released pets or old misidentifications, so treat them as unconfirmed.
Related pages
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.