Western Aquatic Garter Snake
Thamnophis couchii
- KingdomAnimalia (Animals)
- PhylumChordata (Cordats)
- ClassSquamata
- FamilyColubridae (Colúbrids)
- GenusThamnophis (Garter Snakes)
- SpeciesThamnophis couchii (Western Aquatic Garter Snake)
Thamnophis couchii, commonly known as Couch's garter snake, the Sierra garter snake, or the western aquatic garter snake, is a highly aquatic species of snake in the family Colubridae. The species is endemic to the western United States, specifically the Sierra Nevada mountain range. Wikipedia →
10–20% of wildlife watchers report a Western Aquatic Garter Snake sighting in Yosemite National Park, based on 65 days of visitor records from GBIF citizen-science data.
Closest Relatives at Yosemite National Park
Western Terrestrial Garter Snake
Thamnophis elegans
Common Garter Snake
Thamnophis sirtalis
California Mountain Kingsnake
Lampropeltis zonata
Gopher Snake
Pituophis catenifer
Striped Racer
Masticophis lateralis
Ringneck Snake
Diadophis punctatus
Sharp-tailed Snake
Contia tenuis
North American Racer
Coluber constrictor
Coast Night Snake
Hypsiglena ochrorhynchus
California King Snake
Lampropeltis californiae
📅 Monthly Probability
☀️ When They're Spotted
Most active during daytime hours (6am–6pm) · across all parks (global)
Global Distribution
Where this species is recorded worldwide. Restricted to human observations from 2019 onwards — the same kind of record and the same period the probabilities on this page are built from, so collar-tracking studies, camera-trap arrays and museum specimens are excluded. Around Santa Rosa that removes 5,924 GPS fixes from a handful of tagged jaguars.
where this species is recorded (GBIF density — it tracks where observers go, not how likely a sighting is) · parks where it occurs — tap a pin for the sighting probability there
Parks Where Found
| # | Park | Country | Probability |
|---|---|---|---|
| 1 | Sequoia and Kings Canyon National Parks | 🇺🇸 United States | |
| 2 | Yosemite National Park | 🇺🇸 United States |
Quick answers
What are the chances of seeing a Western Aquatic Garter Snake in Yosemite National Park?
About 14% of wildlife watchers report a Western Aquatic Garter Snake sighting in Yosemite National Park, based on 65 days of visitor records from GBIF citizen-science data.
When is the best time to see Western Aquatic Garter Snake in Yosemite National Park?
May has the highest sighting rate for Western Aquatic Garter Snake in Yosemite National Park in our monthly data.