Office of External Affairs
Mountain-Prairie Region


U.S. Fish and Wildlife Service
Mountain-Prairie Region
134 Union Boulevard
Lakewood, Colorado 80228

For release on: June 20, 2011

Larry Crist 801-975-3330 x126

Joy Gober 970-226-9195


The U.S. Fish and Wildlife Service announced today that a petition seeking to protect the Utah population of the Gila monster under the Endangered Species Act (ESA) does not contain substantial scientific information to indicate that the petitioned action may be warranted, because the population does not constitute a distinct population segment (DPS) as defined by the ESA.  The finding will be published in the Federal Register tomorrow. 

Despite this announcement that the species will not receive further consideration for listing under the ESA at this time, we will continue to work with our partners to conserve and protect the Gila monster throughout the species’ range.

Rangewide, the Gila monster occurs in portions of the Mohave Desert in southwestern Utah, southeastern Nevada, southeastern California, and northwestern Arizona; in the Sonoran Desert in southwestern Arizona and Sonora, Mexico; and in small portions of the Chihuahuan Desert in southeastern Arizona and southwestern New Mexico.  In Utah, it is found only in the southern portion of Washington County, which comprises less than one percent of the species’ total range.

We made our determination in response to a petition received on January 27, 2010 from WildEarth Guardians and an individual to list the Utah population of the Gila monster.  Under the ESA, the Service is required to review the petition to decide whether it contains substantial scientific information that listing may be warranted in a process known as a 90-day finding.

We assessed information provided by the petitioners and in our files regarding the Utah population of the Gila monster.  For us to consider the species for listing as threatened or endangered under the ESA, the petitioner would have to present substantial information that the Utah population of the Gila monster is a listable entity. 

We concluded that there was not substantial information that the Utah population was a valid DPS because the population is neither discrete from other Gila monster populations nor significant to the species.

We determined that the Utah population is not discrete from populations in the adjoining States of Arizona and Nevada because there are no barriers separating the populations, and the ecological conditions and behavior of Gila monsters in Utah and the adjoining states are similar. 

We determined that the Utah population is not significant according to our DPS policy because the Gila monster is found in portions of the Mohave Desert in Arizona, California, and Nevada, as well as Utah.  Additionally, Utah contains less than one percent of the species’ total range.

Since there was not substantial information that the Utah population of Gila monster is a DPS, and therefore a listable entity, we did not evaluate the information contained in the petition regarding the conservation status of the Gila monster in Utah.

We will continue to work cooperatively with other federal, state, and private entities to conserve Gila monsters, both in Utah, and throughout the species’ range.  Examples of cooperative efforts include establishment of the Red Cliffs Desert Reserve in Utah; development of Habitat Conservation Plans in Utah and Nevada; and development of a Candidate Conservation Agreement in Nevada.  All of these cooperative efforts include the Gila monster as one of the species of concern that will be protected by the conservation of Mohave Desert habitat.

The Gila monster is the largest native lizard in the U.S.  It has distinctive rounded beadlike bony deposits on the back of its head, limbs, body, and tail that form a pattern of black colored bands on a pale yellow or orange background.  The Gila monster is a slow-moving lizard that feeds almost solely on vertebrate eggs and young in nests.  They can eat large quantities of prey during a single feeding, and as a result can survive on as few as three large meals a year.  Because of its minimal feeding requirements, the Gila monster spends more than 95 percent of its time in underground shelters. 

A copy of the Gila monster finding is available on the Internet at

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