Montana mammals

American Bison in Montana

Bison bison

Native to Montana

Not listed as nonindigenous in Montana by USGS NAS; treated as native to its mapped Montana range.

IUCN Red List status

  1. LC
  2. NT
  3. VU
  4. EN
  5. CR
  6. EW
  7. EX

NT – Near Threatened

Close to qualifying as threatened in the near future.

American Bison in Montana, by the numbers

Common in Montana 12th most recorded of 122 mammals logged in Montana

1,311 occurrence records

Records from 2000–2026.

1,311 total records count every Montana occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 300; the monthly chart covers the 1,273 records with a full observation date.

Field encounter

Where and when you're most likely to encounter an American Bison

Most active: Montana, in October.

Where
MontanaMT
When
October

Observe from a distance and give it room. Never approach, corner, or feed one.

When to be most aware of the American Bison in Montana

Most sightings fall in October.

1,273 Montana occurrence records (iNaturalist and GBIF) by month of year, 2000–2026. Shows when the species is recorded, not a guarantee of presence.

Monthly Montana records (table)
MonthRecords
January31
February16
March21
April39
May68
June92
July73
August101
September83
October649
November90
December10

Monthly american bison occurrence records (iNaturalist and GBIF) in Montana, 2000–2026.

Seasonality

Year-round in Montana, with recorded sightings peaking in October.

Occurrence map

Where American Bison has been recorded in Montana

300 records mapped · zoom and drag to explore

300 Montana records mapped

Where american bison encounters are recorded

Park, forest, or monumentiNaturalist records
Yellowstone National Park 30
Gallatin National Forest 18
Absaroka-Beartooth Wilderness 2
Dome Mountain Wildlife Management Area 1
Glacier National Park 1
Flathead Lake/Wild Horse Island State Park 1
Cameron Bridge Fishing Access Site 1

Protected places with the most american bison records, from the USGS Protected Areas Database plus named mountain ranges, where encounters are most often recorded, not a full breakdown, so they don't sum to the total. Keep your distance and never approach one.

Where it's recorded in Montana

CountyRecords
Sanders County 791
Lake County 161
Park County 80
Gallatin County 56
Lewis and Clark County 54
Phillips County 49
Glacier County 30
Yellowstone County 24
Judith Basin County 16
Beaverhead County 6
Granite County 5
Garfield County 5
19 other counties 34

The complete county distribution, spread across 31 Montana counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Montana’s 1,311 bison records have two gravity wells. Sanders and Lake counties in the northwest together supply more than 950 of them, while Park, Gallatin, and Lewis and Clark counties anchor a second cluster in the Yellowstone country to the south.

Tribal herds in the northwest

The northwestern concentration centers on the tribally managed bison range in the Mission Valley, where a conservation herd grazes bunchgrass foothills under the care of the Confederated Salish and Kootenai Tribes, who took over management of the range from the federal government in recent years. A closely watched herd behind range fences generates a thick stack of reports without meaning bison roam the surrounding counties at large.

Wild migrants at the park’s edge

The southern cluster is different in kind. Yellowstone National Park, Gallatin National Forest, and the Absaroka-Beartooth Wilderness all appear in the record, and some Yellowstone bison still leave the park each winter for lower ground in Montana, the only bison in the lower 48 states that have lived continuously wild since before the nineteenth-century slaughter. Records appear in every month and spike hard in October, when the count jumps to 649, far above any other month. A wild migrant bull in rut or winter stress is among the most dangerous large animals on the continent, and these bison are given wide distance wherever they turn up.

Status in Montana

The overlay treats the bison as native to its mapped Montana range, and USGS NAS does not list it as nonindigenous in the state. Montana holds both managed conservation herds and genuinely wild animals, and the IUCN lists the species globally as Near Threatened.

Occurrence data from iNaturalist and GBIF.

American Bison in other states

View all states →

More mammals in Montana in the atlas

Data & sources

The data and visualizations on this page draw on these open sources:

  • GBIFCC-BY 4.0occurrence records behind the range map, elevation, and record counts
  • iNaturalistCC0 / CC-BY / CC-BY-SAobservations, photos, and audio recordings
  • IUCN Red Listattributed factthe global conservation status
  • USGS NASpublic domainnative / introduced status
  • Natural Earthpublic domainthe relief basemap
  • USFSpublic domainnational-forest boundaries
  • USGS Protected Areas Databasepublic domainthe named parks, forests, and refuges behind "notable places to look"