Common Chuckwalla & Gila Monster

The Common Chuckwalla (Sauromalus ater) shares some of the range with the Gila Monster (Heloderma suspectrum) in the South western portion of the United States, and the very North western portion of Sonora province of Mexico.
 There are 5 subspecies of Chuckwalla. They are Common Chuckwalla (Sauromalus ater)
                        Giant (Aka Painted, San Esteban Island) Chuckwalla (Sauromalus varius)
                                                               Angel Island Chuckwalla (Sauromalus hispidus)
                                                                 Peninsular Chuckwalla (Sauromalus australis)
                                                                    Monserrat Chuckwalla (Sauromalus slevini)
Of the 5, 2 are endangered, the Monserrat Chuckwalla, and San Esteban Island Chuckwalla.
The Common Chuckwalla can be found from Southern California east to southern Nevada, Utah and western Arizona, and south to Baja California and Northwestern Mexico.
They live in rocky areas and eat mostly vegetation and small insects.

The Gila Monster (Heloderma suspectrum) is one of two venomous lizard species in the world. Its cousin, the Mexican Beaded Lizard (Heloderma horridum) is the other.
There are two subspecies of Gila Monster, the Reticulated Gila Monster (Heloderma suspectum suspectum) and the Banded Gila Monster (Heloderma suspectum cinctum)
Reticulated is predominately the southern species, while Banded are the northern being found mostly in the Mojave Desert.
Gila Monsters can be found in Northern Arizona, California, Nevada, Utah, and New Mexico. They are not found in Baja, however.
They live in scrub lands, desert, and woodland areas and avoid open areas. They enjoy water as well, and can be seen in small pools after it rains.
The venom that these lizards have, is a neurotoxin, similar to that of a Coral snake (Micrurus family). The Gila Monster is a quick biter, but not a powerful one. They grind their venom into their prey. The venom gland in a Gila Monster is located in the lower jaw, unlike venomous snakes with the gland in the upper jaw.

Zoos where the Gila Monster can be seen are:

Pacific region
Woodland Park Zoo Seattle, Washington
California Living Museum  Bakersfield, California
Oakland Zoo  Oakland, California
Sacramento Zoo  Sacramento, California
Charles Paddock Zoo  Atascadero, California

Mountain region
Zoo Boise  Boise, Idaho
Hogle Zoo  Salt Lake City, Utah 
Heritage Park Zoo  Prescott, Arizona
Wildlife World  Litchfield Park, Arizona 
Arizona - Sonoran Desert Museum  Tucson, Arizona
Navajo Natonal Zoo  Window Rock, Arizona
Pueblo Zoo  Pueblo, Colorado
American International Rattlesnake Museum  Albuquerque, New Mexico

Central region
Reptile Garden  Rapid City, South Dakota
Lincoln (Folsom) Children's Zoo Lincoln, Nebraska
Oklahoma City Zoo  Oklahoma City, Oklahoma 
Gladys Porter Zoo  Brownsville, Texas
Lake Superior Zoo  Duluth, Minnesota
St. Louis Zoo  St. Louis, Missouri 
Henry Vilas Zoo  Madison, Wisconsin
Glen Oak Zoo  Peoria, Illinois
Birmingham Zoo  Birmingham, Alabama

Eastern region
Potter Park Zoo  Lansing, Michigan
Louisville Zoo  Louisville, Kentucky 
Memphis Zoo  Memphis, Tennessee
Nashville Zoo  Nashville, Tennessee
Cincinnati Zoo  Cincinnati, Ohio
Columbus Zoo & Aquarium  Columbus, Ohio
Toledo Zoo  Toledo, Ohio 
Philadelphia Zoo  Philadelphia, Pennsylvania
Pittsburgh Zoo  Pittsburgh, Pennsylvania
Zoo America North American Wildlife Park  Hershey, Pennsylvania
Ross Park Zoo  Binghamton, New York
Buffalo Zoo  Buffalo, New York 
Seneca Park Zoo  Rochester, New York
Utica Zoo  Utica, New York
Turtle back Zoo  West Orange/ Sussex, New Jersey 
National Zoo Washington D.C.
North Carolina Zoo  Asheboro, North Carolina
Tregembo Animal Park  Wilmington, North Carolina
Zoo Atlanta Atlanta, Georgia
Naples Zoo  Naples, Florida
Central Florida Zoo  Sanford, Florida


Zoos where the Common Chuckwalla can be seen are:

Pacific region
Woodland Park Zoo  Seattle, Washington
California Living Museum  Bakersfieled, California 
Oakland Zoo  Oakland, California
The Living Desert  Palm Desert/ Indian Wells, California

Mountain region
Hogle Zoo  Salt Lake City, Utah
The Arizona - Sonora Desert Museum also features the San Esteban Island Chuckwalla (Sauromalus varius)
Navajo National Zoo  Window Rock, Arizona
Pueblo Zoo  Pueblo, Colorado
Pueblo Zoo also features the San Esteban Island/Painted Chuckwalla (Sauromalus varius)

Central region
Oklahoma City Zoo  Oklahoma City, Oklahoma also features the San Esteban Island/ Painted Chuckwalla (Sauromalus varius)
Amarillo Zoo  Amarillo, Texas
St. Louis Zoo  St. Louis, Missouri
Milwaukee County Zoo  Milwaukee, Wisconsin  features the San Esteban Island/ Painted Chuckwalla (Sauromalus varius) 

Eastern region 
Potter Park Zoo  Lansing, Michigan
Louisville Zoo  Louisville, Kentucky
Buffalo Zoo  Buffalo, New York
Rosamond Gifford Zoo  Syracuse, New York 
Elmwood Park Zoo  Elmwood, Pennsylvania
Zoo America North America Wildlife Park  Hershey, Pennsylvania