Snakes in Montana
Montana has 9 snake species on record, each with at least 10 GBIF records in the state, and 1,278 licensed records in all. The most recorded are the western terrestrial garter snake, the prairie rattlesnake and the gopher snake. One of them is venomous.
Rattlesnakes in Montana
One species of this group is listed for Montana: the prairie rattlesnake, with 344 records (27% of the state's snake records).
Observation records of the prairie rattlesnake in Montana run mostly April through August, peaking in April; most licensed records come from Chouteau County, Carbon County and Wheatland County.
Garter snakes and ribbon snakes in Montana
Garter snakes and ribbon snakes dominate the snake record of Montana: three species and 45% of all records. The most recorded is the western terrestrial garter snake (421), ahead of the common garter snake (109).
Observation records of the western terrestrial garter snake in Montana run mostly May through September, peaking in July; most licensed records come from Sanders County, Lake County and Missoula County. Observation records of the common garter snake in Montana run mostly May through September, peaking in June; most licensed records come from Ravalli County, Lake County and Yellowstone County. Most licensed records of the plains garter snake in Montana come from Phillips County, Roosevelt County and Valley County.
Kingsnakes and milksnakes in Montana
One species of this group is listed for Montana: the central plains milksnake, with 12 records (0.9% of the state's snake records).
Racers, whipsnakes and indigo snakes in Montana
One species of this group is listed for Montana: the eastern racer, with 124 records (10% of the state's snake records).
Most licensed records of the eastern racer in Montana come from Carbon County, Sanders County and Missoula County.
Gopher snakes, bullsnakes and pine snakes in Montana
One species of this group is listed for Montana: the gopher snake, with 147 records (12% of the state's snake records).
Observation records of the gopher snake in Montana run mostly May through September, peaking in May; most licensed records come from Carbon County, Fergus County and Phillips County.
Hognose snakes in Montana
One species of this group is listed for Montana: the plains hog-nosed snake, with 19 records (1% of the state's snake records).
Boas and pythons in Montana
One species of this group is listed for Montana: the northern rubber boa, with 37 records (3% of the state's snake records).
Most licensed records of the northern rubber boa in Montana come from Missoula County, Ravalli County and Lake County.
Where in Montana are snakes recorded most?
Carbon County leads with 124 records (10%), followed by Chouteau County and Sanders County; the top five counties hold 43% of the total. 49 of Montana's 56 counties have at least one licensed snake record.
| # | County | Records | Share |
|---|---|---|---|
| 1 | Carbon County | 124 | 9.7% |
| 2 | Chouteau County | 124 | 9.7% |
| 3 | Sanders County | 112 | 8.8% |
| 4 | Lake County | 108 | 8.5% |
| 5 | Missoula County | 82 | 6.4% |
| 6 | Ravalli County | 67 | 5.2% |
| 7 | Yellowstone County | 65 | 5.1% |
| 8 | Fergus County | 49 | 3.8% |
| 9 | Phillips County | 47 | 3.7% |
| 10 | Big Horn County | 39 | 3.1% |
| 11 | Wheatland County | 37 | 2.9% |
| 12 | Cascade County | 32 | 2.5% |
When do snakes come out in Montana?
Observation records of snakes in Montana run mostly April through September, peaking in June with 25% of them. December through February together hold under 2% of the records, so snakes in Montana are rarely recorded in winter. The sharpest rise comes from March to April.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 0% | 0% | 1% | 11% | 19% | 25% | 19% | 15% | 8% | 2% | 0% | 0% |
Snakes: Montana compared with its neighbors
Montana ranks 44th of 50 states by the number of snake species listed, level with Maine, New Hampshire and Vermont; Texas leads with 86 species.
Of the four states bordering Montana, South Dakota, Idaho and Wyoming list more snake species (Montana: 9 species; South Dakota 16, Idaho 11, Wyoming 11, North Dakota 8).
What snakes are in Montana? All 9 species
Ranked by licensed records in Montana. Species with a profile page are linked.
| # | Species | Family | Records | Share |
|---|---|---|---|---|
| 1 | Western terrestrial garter snake Thamnophis elegans | Colubridae | 421 | 32.9% |
| 2 | Prairie rattlesnake venomous Crotalus viridis | Viperidae | 344 | 26.9% |
| 3 | Gopher snake Pituophis catenifer | Colubridae | 147 | 11.5% |
| 4 | Eastern racer Coluber constrictor | Colubridae | 124 | 9.7% |
| 5 | Common garter snake Thamnophis sirtalis | Colubridae | 109 | 8.5% |
| 6 | Plains garter snake Thamnophis radix | Colubridae | 45 | 3.5% |
| 7 | Northern rubber boa Charina bottae | Boidae | 37 | 2.9% |
| 8 | Plains hog-nosed snake Heterodon nasicus | Colubridae | 19 | 1.5% |
| 9 | Central plains milksnake Lampropeltis gentilis | Colubridae | 12 | 0.9% |
Also recorded in Montana, fewer than 10 times
Beyond the main list, two snake species are known from Montana 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.