Common names: panamint rattlesnake, panamint rattler, more.

Crotalus mitchellii stephensi is a venomous

Venomous snake

"Poisonous snake" redirects here. For true poisonous snakes, see Rhabdophis.Venomous snakes are snakes which have venom glands and specialized teeth for the injection of venom...

 pitviper

Crotalinae

The Crotalinae, commonly known as "pit vipers" or crotaline snakes, are a subfamily of venomous vipers found in Asia and the Americas. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on either side of the head...

 subspecies

Subspecies

Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

 found in southern Nevada

Nevada

Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...

 and adjacent California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

.

Description

Adults are 58-132 cm in length, with an average of 60-91 cm.

According to Klauber (1936), this subspecies is characterized by the absence of the vertical light line on the posterior edge of the prenasals and first supralabials. The supraocular scales

Supraocular scales

In scaled reptiles, supraocular scales are scales on the crown immediately above the eye. The size and shape of these scales are among the many characteristics used to differentiate species from each another....

 are pitted, sutured or with the outer edges broken.

The color pattern consists of a straw, tan, buff, brown or gray ground color, overlaid with a series of buff, gray, brown or deep red-brown blotches. Often, there are gray suffusions on the sides of the body and head, and a scattering of black-tipped scales on the back, especially at the edges of the blotches.

Geographic range

Occurs in desert-mountain areas of eastern slopes of the Sierra Nevada from Mono County, California

Mono County, California

Mono County is a county located in the east central portion of the U.S. state of California, to the east of the Sierra Nevada between Yosemite National Park and Nevada. As of the 2010 census, the population was 14,202, up from 12,853 at the 2000 census...

, east to Nye County, Nevada

Nye County, Nevada

-National protected areas:* Ash Meadows National Wildlife Refuge* Death Valley National Park * Humboldt-Toiyabe National Forest * Spring Mountains National Recreation Area -Demographics:...

, south through southwestern Nevada, southeast to Clark County, Nevada

Clark County, Nevada

-Demographics:As of the census of 2000, there were 1,375,765 people, 512,253 households, and 339,693 families residing within the MSA. The racial makeup of the MSA was 71.6% White , 9.1% Black, 5.7% Asian, 0.8% American Indian and 12.8% of other or mixed race. 22.0% were Hispanic of any race...

, and southwest to central San Bernardino County, California

San Bernardino County, California

San Bernardino County is a county in the U.S. state of California. As of the 2010 census, the population was 2,035,210, up from 1,709,434 as of the 2000 census...

. Found at 900-2400 m altitude.

Reproduction

These snakes are viviparous and the young are born in July and August. Neonates are about 25 cm in length.