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Bighorn Sheep

Ovis canadensis

Mammal · family Bovidae · order Artiodactyla

  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.

Bighorn Sheep
Photo: The High Fin Sperm Whale, CC BY-SA 3.0, via Wikimedia Commons.
Endangered Species Act
Not listed[1]
NatureServe global rank
G4 Apparently Secure[2]
Native in
15 states[3]
Longest recorded life
20.6 years[4]

Bighorn Sheep (Ovis canadensis) is a hoofed mammal in the family Bovidae[5]. It is not listed under the US Endangered Species Act and NatureServe ranks it Apparently Secure worldwide[1][2].

Conservation status

NatureServe gives Bighorn Sheep a global rank of G4 (Apparently Secure) and the same rank, N4, for the United States[2][6]. The IUCN Red List category recorded by NatureServe is Least concern[7]. The species is not listed as endangered or threatened under the US Endangered Species Act in USFWS data[1]. Trade across borders is controlled because it sits in CITES Appendix II[8]. NatureServe also gives each state its own rank, and these differ from state to state[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] Least concern
CITES (international trade)[8] Appendix II
Total population (NatureServe estimate)[10] 10,000 to 100,000 individuals

Where Bighorn Sheep lives

NatureServe lists Bighorn Sheep as native in 15 US states and territories[3]. These are Arizona, California, Colorado, Idaho, Montana, North Dakota, Nebraska, New Mexico, Nevada, Oregon, South Dakota, Texas, Utah, Washington and Wyoming[3]. The states with the most GBIF observation records are California, Colorado, Nevada, Montana and South Dakota[11]. Those counts follow how much people look and report, not how many animals live there[11].

Alaska: not recordedAKMaine: not recordedMEWisconsin: not recordedWIVermont: not recordedVTNew Hampshire: not recordedNHWashington: native, state rank S2WAIdaho: native, state rank S2IDMontana: native, state rank S4MTNorth Dakota: native, state rank SNRNDMinnesota: not recordedMNIllinois: not recordedILMichigan: not recordedMINew York: not recordedNYMassachusetts: not recordedMAOregon: native, state rank S3ORNevada: native, state rank S4NVWyoming: native, state rank S2WYSouth Dakota: native, state rank S4SDIowa: not recordedIAIndiana: not recordedINOhio: not recordedOHPennsylvania: not recordedPANew Jersey: not recordedNJConnecticut: not recordedCTRhode Island: not recordedRICalifornia: native, state rank SNRCAUtah: native, state rank S3UTColorado: native, state rank S4CONebraska: native, state rank S2NEMissouri: not recordedMOKentucky: not recordedKYWest Virginia: not recordedWVVirginia: not recordedVAMaryland: not recordedMDDelaware: not recordedDEArizona: native, state rank S3AZNew Mexico: native, state rank S1NMKansas: 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: native, state rank S2TXFlorida: not recordedFLPuerto Rico: not recordedPR
State presence as recorded by NatureServe[9].
Show state ranks (15 states)
StateRankMeaning
ArizonaS3Vulnerable
CaliforniaSNRNot Ranked
ColoradoS4Apparently Secure
IdahoS2Imperiled
MontanaS4Apparently Secure
NebraskaS2Imperiled
NevadaS4Apparently Secure
New MexicoS1Critically Imperiled
North DakotaSNRNot Ranked
OregonS3Vulnerable
South DakotaS4Apparently Secure
TexasS2Imperiled
UtahS3Vulnerable
WashingtonS2Imperiled
WyomingS2Imperiled

Habitat

NatureServe records many habitat types for Bighorn Sheep, including desert, alpine, grassland, shrubland, woodland and riparian areas[12]. They also use cliffs and bare rock, talus and scree[12]. The notes describe open grassland or shrub country in mountains, foothills and river canyons[13]. Steep, rocky escape terrain is an important part of their habitat[13].

Habitat types recorded by NatureServe[12]

Size, diet and lifespan

Bighorn Sheep are herbivores that mostly graze on grass and other soft plants, and shrubs can make up a good share of the diet too[14][15]. The diet changes with the seasons[15]. NatureServe records a typical length of 185 cm (73 in) and a typical adult weight of 150 kg (331 lb)[16][17]. A female usually has a litter of 1[18]. Females reach sexual maturity at 707 days[19]. The oldest known Bighorn Sheep lived in captivity, and this is a record, not a typical lifespan[4].

Trait Value
Typical length[16] 185 cm (73 in)
Typical adult weight[17] 150 kg (331 lb)
Longest recorded lifespan (AnAge)[4] 20.6 years (captivity)
Litter or clutch size[18] 1
Gestation or incubation[20] 180 days
Female maturity[19] 707 days (about 1.9 years)
Food habits[14] Herbivore
Active[21] nocturnal, crepuscular, diurnal
Migration[22] local migrant

Estimated diet composition (EltonTraits 1.0)[23]

  • 100% other plant material

When to look for it

Bighorn Sheep are active in the daytime[24]. Feeding often peaks in early morning and at dusk, and feeding periods are longer in winter[25]. NatureServe calls them local migrants, though populations can differ[22]. Most populations outside low deserts move between a high summer range and a lower winter range, and some use as many as five ranges in a year[26]. GBIF records peak in June, July and August, which reflects when people look and report[27].

January: 1,197 recordsJanFebruary: 1,246 recordsFebMarch: 1,581 recordsMarApril: 1,551 recordsAprMay: 1,804 recordsMayJune: 2,116 recordsJunJuly: 2,430 recordsJulAugust: 2,220 recordsAugSeptember: 1,739 recordsSepOctober: 1,355 recordsOctNovember: 1,386 recordsNovDecember: 1,196 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[27].
Show records by month
MonthRecords
January1,197
February1,246
March1,581
April1,551
May1,804
June2,116
July2,430
August2,220
September1,739
October1,355
November1,386
December1,196

Where to see it

National Park Service species lists record Bighorn Sheep as present in 36 park units[28]. Present means the park has a confirmed record, not that sightings are common.

And 12 more park units.

States with the most GBIF observation records: California, Colorado, Nevada, Montana, South Dakota[11]. These counts follow where people look and report, not population size.

Safety around this animal

These tips are quoted in summary from official agencies. We add no advice of our own. Follow local rules and the agency pages linked below.

From National Park Service (Yellowstone)

  • In Yellowstone, the National Park Service asks visitors to stay at least 25 yards (23 m) from large animals such as bison and elk.
  • If the animal moves closer, back away. Approaching wildlife close enough to disturb or displace it is illegal in the park.
  • Never feed wildlife. Use binoculars or a long camera lens instead of moving closer.

Source: National Park Service (Yellowstone)[29]

Questions people ask

Are Bighorn Sheep endangered?
Bighorn Sheep are not listed as endangered or threatened under the US Endangered Species Act in USFWS data[1]. NatureServe ranks them G4 (Apparently Secure) worldwide[2].
Where do Bighorn Sheep live?
NatureServe lists them as native in 15 US states and territories, from Washington and California east to the Dakotas and Texas[3].
What do Bighorn Sheep eat?
They are herbivores that mostly graze on grass and forbs, and the diet also includes shrubs and changes with the seasons[14][15].
How big are Bighorn Sheep?
NatureServe records a typical length of 185 cm (73 in) and a typical adult weight of 150 kg (331 lb)[16][17].
How long do Bighorn Sheep live?
The longest recorded lifespan comes from an animal in captivity[4]. It is a record, not a typical lifespan[4].

Facts and sources

  1. Bighorn Sheep 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 Bighorn Sheep: G4 (Apparently Secure). NatureServe Explorer
  3. NatureServe lists Bighorn Sheep as native in 15 US states and territories: Arizona, California, Colorado, Idaho, Montana, North Dakota, Nebraska, New Mexico, Nevada, Oregon, South Dakota, Texas, Utah, Washington, Wyoming. NatureServe Explorer
  4. Maximum recorded lifespan in AnAge: 20.6 years in captivity. This is a record, not a typical lifespan. AnAge
  5. Bighorn Sheep (Ovis canadensis) is a mammal in the family Bovidae, order Artiodactyla. NatureServe Explorer
  6. NatureServe national rank in the United States: N4 (Apparently Secure). NatureServe Explorer
  7. IUCN Red List category as recorded by NatureServe: Least concern. NatureServe Explorer
  8. CITES listing recorded by NatureServe: Appendix II (controls on international trade). NatureServe Explorer
  9. NatureServe state ranks for Bighorn Sheep (map and table on this page). NatureServe Explorer
  10. NatureServe estimate of total adult population (global, as a range): 10,000 to 100,000 individuals. NatureServe Explorer
  11. US states with the most GBIF observation records of Bighorn Sheep: California, Colorado, Nevada, Montana, South Dakota. Record counts follow observer effort, not population size. GBIF
  12. Habitat types NatureServe records for Bighorn Sheep: Woodland - hardwood, Woodland - conifer, Woodland - mixed, Shrubland/chaparral, Grassland/herbaceous, Desert, Alpine, Bare rock/talus/scree, Cliff, Riparian. NatureServe Explorer
  13. NatureServe notes on habitat for Bighorn Sheep. NatureServe Explorer
  14. Adult food habits recorded by NatureServe: Herbivore. NatureServe Explorer
  15. NatureServe notes on food for Bighorn Sheep. NatureServe Explorer
  16. Typical length recorded by NatureServe: 185 cm (73 in). NatureServe Explorer
  17. Typical adult weight recorded by NatureServe: 150 kg (331 lb). NatureServe Explorer
  18. Typical litter or clutch size in AnAge: 1. AnAge
  19. Age at female sexual maturity in AnAge: 707 days (about 1.9 years). AnAge
  20. Gestation or incubation period in AnAge: 180 days. AnAge
  21. Activity time in EltonTraits 1.0: nocturnal, crepuscular, diurnal. EltonTraits 1.0
  22. NatureServe migration category for Bighorn Sheep: local migrant (populations can differ). NatureServe Explorer
  23. Estimated diet composition in EltonTraits 1.0: 100% other plant material. EltonTraits 1.0
  24. Adult activity patterns recorded by NatureServe: Diurnal. NatureServe Explorer
  25. NatureServe notes on phenology for Bighorn Sheep. NatureServe Explorer
  26. NatureServe notes on migration for Bighorn Sheep. NatureServe Explorer
  27. GBIF observation records of Bighorn Sheep in the US by month (chart on this page). GBIF
  28. NPSpecies park lists recording Bighorn Sheep as present (list on this page). NPS NPSpecies
  29. Safety guidance from National Park Service (Yellowstone). National Park Service

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: The High Fin Sperm Whale, CC BY-SA 3.0, via Wikimedia Commons.