SpeciesFacts

All species › Reptiles › Gila Monster

Gila Monster

Heloderma suspectum

Reptile · family Helodermatidae · order Squamata

  1. G1
    Critically imperiled
  2. G2
    Imperiled
  3. G3
    Vulnerable
  4. G4
    Apparently secure
  5. G5
    Secure

NatureServe global rank G4: apparently secure[2].

Updated October 30, 2026. Published by Humblebee.

Gila Monster
Photo: Josh Olander, CC BY 4.0, via Wikimedia Commons.
Endangered Species Act
Not listed[1]
NatureServe global rank
G4 Apparently Secure[2]
Native in
5 states[3]
Longest recorded life
28.9 years[4]

The Gila monster is a lizard in the family Helodermatidae[5]. It is not listed under the US Endangered Species Act[1], and NatureServe lists it as native in 5 US states: Arizona, California, New Mexico, Nevada and Utah[3].

Conservation status

NatureServe ranks the Gila monster G4, Apparently Secure, across its whole range[2] and N4, Apparently Secure, in the United States[6]. The IUCN Red List category recorded by NatureServe is Near threatened[7]. It is not listed as endangered or threatened under the ESA[1], but international trade is controlled because it is on CITES Appendix II[8]. NatureServe also gives it a separate rank in each of the 5 states where it lives, shown in the table on this page[9].

Status Value
Endangered Species Act[1] Not listed
NatureServe global rank[2] G4 (Apparently Secure)
NatureServe US rank[6] N4 (Apparently Secure)
IUCN Red List (via NatureServe)[7] Near threatened
CITES (international trade)[8] Appendix II

Where Gila Monster lives

In the US, the Gila monster is native to the Southwest, in Arizona, California, New Mexico, Nevada and Utah[3]. People report it on GBIF from all five of these states, with Arizona at the top of the list[10]. These reports follow where observers look, not how many lizards live there[10]. The National Park Service lists it in 10 park units[11].

Alaska: not recordedAKMaine: not recordedMEWisconsin: not recordedWIVermont: not recordedVTNew Hampshire: not recordedNHWashington: not recordedWAIdaho: not recordedIDMontana: not recordedMTNorth Dakota: not recordedNDMinnesota: not recordedMNIllinois: not recordedILMichigan: not recordedMINew York: not recordedNYMassachusetts: not recordedMAOregon: not recordedORNevada: native, state rank S2NVWyoming: not recordedWYSouth Dakota: not recordedSDIowa: not recordedIAIndiana: not recordedINOhio: not recordedOHPennsylvania: not recordedPANew Jersey: not recordedNJConnecticut: not recordedCTRhode Island: not recordedRICalifornia: native, state rank SNRCAUtah: native, state rank S2UTColorado: not recordedCONebraska: not recordedNEMissouri: not recordedMOKentucky: not recordedKYWest Virginia: not recordedWVVirginia: not recordedVAMaryland: not recordedMDDelaware: not recordedDEArizona: native, state rank S4AZNew Mexico: native, state rank S2NMKansas: not recordedKSArkansas: not recordedARTennessee: not recordedTNNorth Carolina: not recordedNCSouth Carolina: not recordedSCDistrict of Columbia: not recordedDCOklahoma: not recordedOKLouisiana: not recordedLAMississippi: not recordedMSAlabama: not recordedALGeorgia: not recordedGAHawaii: not recordedHITexas: not recordedTXFlorida: not recordedFLPuerto Rico: not recordedPR
State presence as recorded by NatureServe[9].
Show state ranks (5 states)
StateRankMeaning
ArizonaS4Apparently Secure
CaliforniaSNRNot Ranked
NevadaS2Imperiled
New MexicoS2Imperiled
UtahS2Imperiled

Habitat

NatureServe records the Gila monster in desert, shrubland and chaparral, hardwood woodland and riparian areas, meaning land along streams[12]. It lives in desert scrub and desert grassland, and less often in oak or pine and oak woodland[13]. In Arizona it seems to do better in wetter, rocky desert than in dry, sandy desert, where it stays close to rocky hills and mountains[13].

Habitat types recorded by NatureServe[12]

Size, diet and lifespan

The Gila monster is a meat eater that also eats insects and other small invertebrates[14]. Its meals include small mammals, bird and reptile eggs, other lizards, insects and dead animals, and it finds food mostly by smell[15]. A typical length is 61 cm (24 in)[16]. Females lay eggs mainly in July and August, about 6 per clutch on average and up to 13[17]. In Arizona the eggs are reported to stay underground through winter and hatch the next spring after about 10 months[17]. The longest recorded lifespan in the AnAge database comes from an animal kept in captivity[4].

Trait Value
Typical length[16] 61 cm (24 in)
Longest recorded lifespan (AnAge)[4] 28.9 years (captivity)
Food habits[14] Carnivore, Invertivore
Migration[18] non-migrant, local migrant

When to look for it

The Gila monster is active by day and at dawn and dusk, which is called crepuscular[19]. In Arizona and Utah it is out mainly from early spring to early fall, and in summer it may come out mostly around dusk and at night or rest in burrows[20]. It does not make long migrations, though some move short distances between winter and summer spots[18][21]. GBIF reports peak in April, May and August, which shows when people see it, not how many there are[22].

January: 6 recordsJanFebruary: 34 recordsFebMarch: 232 recordsMarApril: 615 recordsAprMay: 605 recordsMayJune: 287 recordsJunJuly: 360 recordsJulAugust: 433 recordsAugSeptember: 178 recordsSepOctober: 54 recordsOctNovember: 26 recordsNovDecember: 13 recordsDec
US observation records on GBIF by month, all years. The three months with the most records are highlighted. Records show when people look and report, not how many animals there are[22].
Show records by month
MonthRecords
January6
February34
March232
April615
May605
June287
July360
August433
September178
October54
November26
December13

Where to see it

National Park Service species lists record Gila Monster as present in 10 park units[11]. Present means the park has a confirmed record, not that sightings are common.

States with the most GBIF observation records: Arizona, Nevada, New Mexico, Utah, California[10]. These counts follow where people look and report, not population size.

Questions people ask

Is the Gila monster endangered?
No. It is not listed as endangered or threatened under the US Endangered Species Act[1]. NatureServe ranks it Apparently Secure[2], and the IUCN category it records is Near threatened[7].
Where do Gila monsters live in the US?
NatureServe lists it as native in Arizona, California, New Mexico, Nevada and Utah[3]. It lives mostly in desert, shrubland and nearby habitats[12].
What do Gila monsters eat?
It eats small mammals, eggs of birds and reptiles, lizards, insects and dead animals[15]. It tracks food mainly by smell[15].
How big is a Gila monster?
NatureServe records a typical length of 61 cm (24 in)[16].
How long do Gila monsters live?
The oldest known Gila monster in the AnAge database was an animal kept in captivity[4]. That is a record, not a typical lifespan[4].

Facts and sources

  1. Gila Monster is not listed as endangered or threatened under the US Endangered Species Act in USFWS ECOS data (checked 2026-10-30). USFWS ECOS
  2. NatureServe global conservation status rank for Gila Monster: G4 (Apparently Secure). NatureServe Explorer
  3. NatureServe lists Gila Monster as native in 5 US states and territories: Arizona, California, New Mexico, Nevada, Utah. NatureServe Explorer
  4. Maximum recorded lifespan in AnAge: 28.9 years in captivity. This is a record, not a typical lifespan. AnAge
  5. Gila Monster (Heloderma suspectum) is a reptile in the family Helodermatidae, order Squamata. NatureServe Explorer
  6. NatureServe national rank in the United States: N4 (Apparently Secure). NatureServe Explorer
  7. IUCN Red List category as recorded by NatureServe: Near threatened. NatureServe Explorer
  8. CITES listing recorded by NatureServe: Appendix II (controls on international trade). NatureServe Explorer
  9. NatureServe state ranks for Gila Monster (map and table on this page). NatureServe Explorer
  10. US states with the most GBIF observation records of Gila Monster: Arizona, Nevada, New Mexico, Utah, California. Record counts follow observer effort, not population size. GBIF
  11. NPSpecies park lists recording Gila Monster as present (list on this page). NPS NPSpecies
  12. Habitat types NatureServe records for Gila Monster: Woodland - hardwood, Shrubland/chaparral, Desert, Riparian. NatureServe Explorer
  13. NatureServe notes on habitat for Gila Monster. NatureServe Explorer
  14. Adult food habits recorded by NatureServe: Carnivore, Invertivore. NatureServe Explorer
  15. NatureServe notes on food for Gila Monster. NatureServe Explorer
  16. Typical length recorded by NatureServe: 61 cm (24 in). NatureServe Explorer
  17. NatureServe notes on reproduction for Gila Monster. NatureServe Explorer
  18. NatureServe migration category for Gila Monster: non-migrant, local migrant (populations can differ). NatureServe Explorer
  19. Adult activity patterns recorded by NatureServe: Diurnal, Crepuscular. NatureServe Explorer
  20. NatureServe notes on phenology for Gila Monster. NatureServe Explorer
  21. NatureServe notes on migration for Gila Monster. NatureServe Explorer
  22. GBIF observation records of Gila Monster in the US by month (chart on this page). GBIF

Status, range and habitat come from NatureServe Explorer (CC BY 4.0) and USFWS ECOS at the snapshot date. Listings change by federal rule. State lists are where NatureServe records the species, not a promise that you will see it there. Never name a place smaller than a state. GBIF and park records count observations and checklists. They show where and when people report the species, not how many animals live there.

NatureServe. 2026. NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org. (Accessed: October 30, 2026). Licensed under CC BY 4.0; SpeciesFacts selected and summarized it.

Photo: Josh Olander, CC BY 4.0, via Wikimedia Commons.