Thamnophis elegans
Silhouette: Alex Slavenko · PhyloPic
In 3 days ~50% in a week ~80%
The western terrestrial garter snake (Thamnophis elegans) is a western North American species of colubrid snake. At least five subspecies are recognized. Thamnophis elegans is found in central British Columbia, central Alberta, and southwestern Manitoba in Canada. It can be found in the western United States, as far east as western Nebraska and the Oklahoma Panhandle. An isolated population occurs in Baja California, Mexico.
Six subspecies have been identified, although the validity of some of them is debated. Most western terrestrial garter snakes have a yellow, light orange, or white dorsal stripe, accompanied by two stripes of the same color, one on each side. Some varieties have red or black spots between the dorsal stripe and the side stripes. It is an immensely variable species, and even the most experienced herpetologists have trouble with its identification. They are medium-sized snakes, usually 46–104 cm (18–41 in).
Like many species of North American garter snake, the western terrestrial garter snake possesses a mildly venomous saliva. Specimens collected from Idaho and Washington produced venom with myonecrotic (muscle... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Grand Teton National Park | 🇺🇸 United States | |
| 2 | Rocky Mountain National Park | 🇺🇸 United States | |
| 3 | Sequoia and Kings Canyon National Parks | 🇺🇸 United States | |
| 4 | Zion National Park | 🇺🇸 United States | |
| 5 | Yellowstone National Park | 🇺🇸 United States | |
| 6 | Glacier National Park | 🇺🇸 United States | |
| 7 | Yosemite National Park | 🇺🇸 United States | |
| 8 | Redwood National Park | 🇺🇸 United States | |
| 9 | Banff National Park | 🇨🇦 Canada | |
| 10 | Great Bear Rainforest | 🇨🇦 Canada | |
| 11 | Jasper National Park | 🇨🇦 Canada | |
| 12 | Grand Canyon National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Denver | 🇺🇸 United States | |
| 2 | Salt Lake City | 🇺🇸 United States | |
| 3 | Calgary | 🇨🇦 Canada | |
| 4 | San Francisco | 🇺🇸 United States | |
| 5 | Sacramento | 🇺🇸 United States | |
| 6 | Seattle | 🇺🇸 United States | |
| 7 | Vancouver | 🇨🇦 Canada |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | The Living Planet Aquarium | 🇺🇸 United States | |
| 2 | Grizzly & Wolf Discovery Center | 🇺🇸 United States | |
| 3 | Sequoia Park Zoo | 🇺🇸 United States |
Possible
About 20% of wildlife watchers report a Western Terrestrial Garter Snake sighting in Yosemite National Park on a given day, based on 85 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 6th most-seen of the 17 reptiles we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.
August
In that month about 40% of wildlife watchers report a Western Terrestrial Garter Snake in Yosemite National Park on a given day, against under 5% in November to March, the lowest months. That is one of Yosemite National Park's driest months, with about 30 mm of rain against 220 mm in January.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Western Terrestrial Garter Snake sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
7th of 12
Of the 12 parks where we can rate Western Terrestrial Garter Snake sightings, Yosemite National Park ranks 7th at about 20%. The best odds are in Grand Teton National Park (United States, about 40%), Rocky Mountain National Park (United States, about 30%) and Sequoia and Kings Canyon National Parks (United States, about 30%).
GBIF citizen-science records
It is estimated from how often the Western Terrestrial Garter Snake is recorded against all the reptiles logged in Yosemite National Park (85 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
