Hypsiglena chlorophaea
Silhouette: Jose Carlos Arenas-Monroy · PhyloPic
In 3 days ~30% in a week ~60%
Hypsiglena chlorophaea, commonly known as the desert nightsnake, is a species of rear-fanged colubrid snake native to North America. It is found throughout regions of Mexico, the United States, and in a small, isolated population in British Columbia, Canada. Known for its highly secretive, nocturnal nature, it is a mildly venomous species that poses no danger to humans.
The desert nightsnake is a small, slender snake, typically measuring between 30 and 66 cm (12 to 26 inches) in total length. Females are generally longer and heavier than males. Its base coloration ranges from beige or yellowish to grey, overlaid with dark grey-brown blotches that usually form offset pairs down its back. It has three distinct, elongated dark blotches on its neck and behind each eye.
Because of its triangular-shaped head, vertical pupils, and blotched patterning, it is frequently mistaken for a juvenile rattlesnake. However, the desert nightsnake lacks a rattle and possesses smooth dorsal scales. It is an opisthoglyphous (rear-fanged) snake, meaning its enlarged, grooved teeth are located at the back of the upper jaw to help subdue prey.
The desert nightsnake has three... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Saguaro National Park | 🇺🇸 United States | |
| 2 | Death Valley National Park | 🇺🇸 United States | |
| 3 | Zion National Park | 🇺🇸 United States | |
| 4 | Grand Canyon National Park | 🇺🇸 United States | |
| 5 | Joshua Tree National Park | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Desert Nightsnake sighting in Death Valley National Park on a given day, based on 18 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 27th most-seen of the 30 reptiles we can rate there. Over three days the chance rises to about 30%, and over a week to about 60%, if each day is a fresh chance.
August
In that month about 20% of wildlife watchers report a Desert Nightsnake in Death Valley National Park on a given day, against under 5% in June and December–February, the lowest months. That is one of Death Valley National Park's wettest months, with about 30 mm of rain against 5 mm in June.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most Desert Nightsnake sightings with a recorded time, and about 8 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
Among the best
Of the 5 parks where we can rate Desert Nightsnake sightings, Death Valley National Park ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Saguaro National Park (United States, about 10%).
Same family: Colubridae
The closest relatives of the Desert Nightsnake that you can see in Death Valley National Park (family Colubridae, Colubrid Snakes) are Coachwhip (about 30%), Gopher Snake (about 30%) and Western Patch-nosed Snake (about 30%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Desert Nightsnake is recorded against all the reptiles logged in Death Valley National Park (18 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.
