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American Bison

Bos bison

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.

Endangered Species Act
Not listed[1]
NatureServe global rank
G4 Apparently Secure[2]
Native in
7 states[3]
Typical length
150 in[4]

The American Bison (Bos bison) is a mammal in the family Bovidae[5]. NatureServe ranks it G4, Apparently Secure, and it is not listed under the US Endangered Species Act[2][1].

Conservation status

NatureServe gives the American Bison a global rank of G4 and a national rank for the United States of N4, and both mean Apparently Secure[2][6]. The IUCN Red List category recorded by NatureServe is Near threatened[7]. The USFWS ECOS data checked on 2026-10-30 show it is not listed as endangered or threatened under the Endangered Species Act[1]. NatureServe estimates the global adult population at 10,000 to >1,000,000 individuals[8].

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
Total population (NatureServe estimate)[8] 10,000 to >1,000,000 individuals

Where American Bison lives

NatureServe lists the American Bison as native in 7 states: Alaska, California, Idaho, Montana, South Dakota, Utah and Wyoming[3]. It is introduced, which means not native, in Arizona[9]. NatureServe ranks it as extirpated or possibly extirpated in many other states, including Texas, Kansas, Nebraska, North Dakota, Oklahoma and Colorado[10]. Park service lists record it in 6 park units[11].

Alaska: native, state rank SNRAKMaine: not recordedMEWisconsin: extirpated or possibly extirpated, state rank SXWIVermont: not recordedVTNew Hampshire: not recordedNHWashington: extirpated or possibly extirpated, state rank SXWAIdaho: native, state rank SNRIDMontana: native, state rank S3MTNorth Dakota: extirpated or possibly extirpated, state rank SXNDMinnesota: extirpated or possibly extirpated, state rank SXMNIllinois: extirpated or possibly extirpated, state rank SXILMichigan: extirpated or possibly extirpated, state rank SXMINew York: extirpated or possibly extirpated, state rank SXNYMassachusetts: extirpated or possibly extirpated, state rank SXMAOregon: extirpated or possibly extirpated, state rank SXORNevada: extirpated or possibly extirpated, state rank SXNVWyoming: native, state rank S1WYSouth Dakota: native, state rank S3SDIowa: extirpated or possibly extirpated, state rank SXIAIndiana: extirpated or possibly extirpated, state rank SXINOhio: extirpated or possibly extirpated, state rank SXOHPennsylvania: not recordedPANew Jersey: not recordedNJConnecticut: not recordedCTRhode Island: not recordedRICalifornia: native, state rank SNRCAUtah: native, state rank S2UTColorado: extirpated or possibly extirpated, state rank SXCONebraska: extirpated or possibly extirpated, state rank SXNEMissouri: extirpated or possibly extirpated, state rank SXMOKentucky: extirpated or possibly extirpated, state rank SXKYWest Virginia: extirpated or possibly extirpated, state rank SXWVVirginia: extirpated or possibly extirpated, state rank SXVAMaryland: extirpated or possibly extirpated, state rank SXMDDelaware: extirpated or possibly extirpated, state rank SXDEArizona: introduced, state rank SNAAZNew Mexico: extirpated or possibly extirpated, state rank SXNMKansas: extirpated or possibly extirpated, state rank SXKSArkansas: extirpated or possibly extirpated, state rank SXARTennessee: extirpated or possibly extirpated, state rank SXTNNorth Carolina: extirpated or possibly extirpated, state rank SXNCSouth Carolina: extirpated or possibly extirpated, state rank SXSCDistrict of Columbia: extirpated or possibly extirpated, state rank SXDCOklahoma: extirpated or possibly extirpated, state rank SXOKLouisiana: extirpated or possibly extirpated, state rank SXLAMississippi: extirpated or possibly extirpated, state rank SXMSAlabama: extirpated or possibly extirpated, state rank SXALGeorgia: extirpated or possibly extirpated, state rank SXGAHawaii: not recordedHITexas: extirpated or possibly extirpated, state rank SHTXFlorida: extirpated or possibly extirpated, state rank SXFLPuerto Rico: not recordedPR
State presence as recorded by NatureServe[12].
Show state ranks (43 states)
StateRankMeaning
AlabamaSXPresumed Extirpated
AlaskaSNRNot Ranked
ArizonaSNANot Applicable
ArkansasSXPresumed Extirpated
CaliforniaSNRNot Ranked
ColoradoSXPresumed Extirpated
DelawareSXPresumed Extirpated
District of ColumbiaSXPresumed Extirpated
FloridaSXPresumed Extirpated
GeorgiaSXPresumed Extirpated
IdahoSNRNot Ranked
IllinoisSXPresumed Extirpated
IndianaSXPresumed Extirpated
IowaSXPresumed Extirpated
KansasSXPresumed Extirpated
KentuckySXPresumed Extirpated
LouisianaSXPresumed Extirpated
MarylandSXPresumed Extirpated
MassachusettsSXPresumed Extirpated
MichiganSXPresumed Extirpated
MinnesotaSXPresumed Extirpated
MississippiSXPresumed Extirpated
MissouriSXPresumed Extirpated
MontanaS3Vulnerable
NebraskaSXPresumed Extirpated
NevadaSXPresumed Extirpated
New MexicoSXPresumed Extirpated
New YorkSXPresumed Extirpated
North CarolinaSXPresumed Extirpated
North DakotaSXPresumed Extirpated
OhioSXPresumed Extirpated
OklahomaSXPresumed Extirpated
OregonSXPresumed Extirpated
South CarolinaSXPresumed Extirpated
South DakotaS3Vulnerable
TennesseeSXPresumed Extirpated
TexasSHPossibly Extirpated
UtahS2Imperiled
VirginiaSXPresumed Extirpated
WashingtonSXPresumed Extirpated
West VirginiaSXPresumed Extirpated
WisconsinSXPresumed Extirpated
WyomingS1Critically Imperiled

Habitat

NatureServe records several habitat types for the American Bison. These are hardwood, conifer and mixed woodland, savanna, grassland and herbaceous wetland[13]. In the south it lives on open plains and grasslands, and in the north it uses woodland, forest openings, meadows and river valleys[14]. Like other big grazers, it is drawn to burned areas in the following growing season[14].

Habitat types recorded by NatureServe[13]

Size and diet

The American Bison is a herbivore that mostly grazes on grasses, forbs and sedges[15][16]. NatureServe records a typical length of 380 cm (150 in) and a typical adult weight of 907 kg (2000 lb)[4][17]. Most mating happens in July and August, and the calf grows for many months before birth[18]. A cow normally has 1 calf, born mainly from mid-April to early June[18]. NatureServe gives a recorded life span range of 18 to 22 years, which is a record and not a typical lifespan[18].

Trait Value
Typical length[4] 380 cm (150 in)
Typical adult weight[17] 907 kg (2000 lb)
Food habits[15] Herbivore
Migration[19] long-distance migrant

When to look for it

The American Bison is diurnal, which means active in the daytime, especially early morning and late afternoon[20][21]. It was once a long-distance migrant that moved across the prairie in spring and fall, and it probably went south a few hundred miles for winter[19][22]. Today its movements in the US are mostly limited to parks and the areas near them[22]. Observation records on GBIF peak in July, August and October, but they show when people look and report, not how many animals there are[23].

January: 691 recordsJanFebruary: 628 recordsFebMarch: 857 recordsMarApril: 1,217 recordsAprMay: 2,269 recordsMayJune: 3,136 recordsJunJuly: 3,533 recordsJulAugust: 3,167 recordsAugSeptember: 2,391 recordsSepOctober: 3,756 recordsOctNovember: 1,955 recordsNovDecember: 548 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[23].
Show records by month
MonthRecords
January691
February628
March857
April1,217
May2,269
June3,136
July3,533
August3,167
September2,391
October3,756
November1,955
December548

Where to see it

National Park Service species lists record American Bison as present in 6 park units[11]. Present means the park has a confirmed record, not that sightings are common.

States with the most GBIF observation records: Wyoming, South Dakota, Kentucky, North Dakota, Montana[24]. These counts follow where people look and report, not population size.

Questions people ask

Is the American Bison endangered?
It is not listed as endangered or threatened under the US Endangered Species Act[1]. NatureServe ranks it G4, Apparently Secure, and the IUCN category it records is Near threatened[2][7].
Where does the American Bison live?
NatureServe lists it as native in Alaska, California, Idaho, Montana, South Dakota, Utah and Wyoming[3]. It is introduced in Arizona[9].
What does the American Bison eat?
It is a herbivore that mainly grazes on grasses, forbs and sedges[15][16].
How big is the American Bison?
NatureServe records a typical length of 380 cm (150 in) and a typical adult weight of 907 kg (2000 lb)[4][17].
When can you see the American Bison?
It is active in the daytime, especially early morning and late afternoon[20][21]. Observation records on GBIF are highest in July, August and October, which reflects when people report it[23].

Facts and sources

  1. American Bison 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 American Bison: G4 (Apparently Secure). NatureServe Explorer
  3. NatureServe lists American Bison as native in 7 US states and territories: Alaska, California, Idaho, Montana, South Dakota, Utah, Wyoming. NatureServe Explorer
  4. Typical length recorded by NatureServe: 380 cm (150 in). NatureServe Explorer
  5. American Bison (Bos bison) 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: Near threatened. NatureServe Explorer
  8. NatureServe estimate of total adult population (global, as a range): 10,000 to >1,000,000 individuals. NatureServe Explorer
  9. NatureServe lists American Bison as introduced (not native) in: Arizona. NatureServe Explorer
  10. NatureServe ranks American Bison as extirpated or possibly extirpated (SX or SH) in: Alabama, Arkansas, Colorado, the District of Columbia, Delaware, Florida, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Michigan,... NatureServe Explorer
  11. NPSpecies park lists recording American Bison as present (list on this page). NPS NPSpecies
  12. NatureServe state ranks for American Bison (map and table on this page). NatureServe Explorer
  13. Habitat types NatureServe records for American Bison: Woodland - hardwood, Woodland - conifer, Woodland - mixed, Savanna, Grassland/herbaceous, Herbaceous wetland. NatureServe Explorer
  14. NatureServe notes on habitat for American Bison. NatureServe Explorer
  15. Adult food habits recorded by NatureServe: Herbivore. NatureServe Explorer
  16. NatureServe notes on food for American Bison. NatureServe Explorer
  17. Typical adult weight recorded by NatureServe: 907 kg (2000 lb). NatureServe Explorer
  18. NatureServe notes on reproduction for American Bison. NatureServe Explorer
  19. NatureServe migration category for American Bison: long-distance migrant (populations can differ). NatureServe Explorer
  20. Adult activity patterns recorded by NatureServe: Diurnal. NatureServe Explorer
  21. NatureServe notes on phenology for American Bison. NatureServe Explorer
  22. NatureServe notes on migration for American Bison. NatureServe Explorer
  23. GBIF observation records of American Bison in the US by month (chart on this page). GBIF
  24. US states with the most GBIF observation records of American Bison: Wyoming, South Dakota, Kentucky, North Dakota, Montana. Record counts follow observer effort, not population size. 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.