South Dakota mammals

Western Deer Mouse in South Dakota

Peromyscus sonoriensis

Native to South Dakota

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

IUCN Red List status

NE – Not Evaluated

Not yet assessed against IUCN Red List criteria.

Western deer mouse sheltering in a rock creviceWestern deer mouse sniffing gravel with its white feet visibleWestern deer mouse close-up showing its large ears and long whiskers
Photo: Logan Stecker · CC0Western deer mouse sheltering in a rock crevicePhoto: Aerin Jacob · CC BY 4.0Western deer mouse sniffing gravel with its white feet visiblePhoto: Liam Steele · CC0Western deer mouse close-up showing its large ears and long whiskers

Western Deer Mouse in South Dakota, by the numbers

Rare in South Dakota 46th most recorded of 63 mammals logged in South Dakota

12 occurrence records
9 with iNaturalist photos
Dec 30, 2025 Last seen in South Dakota

Records from 2000–2026.

When to look for the Western Deer Mouse in South Dakota

Most sightings fall in December.

12 South Dakota occurrence records (iNaturalist and GBIF) by month of year, 2000–2026. Shows when the species is recorded, not a guarantee of presence. Based on a small number of dated records; the seasonal pattern may not be representative.

Monthly South Dakota records (table)
MonthRecords
January0
February0
March0
April2
May1
June0
July1
August0
September1
October2
November0
December5

Monthly western deer mouse occurrence records (iNaturalist and GBIF) in South Dakota, 2000–2026.

Seasonality

Year-round in South Dakota, with recorded sightings peaking in December.

Occurrence map

Where Western Deer Mouse has been recorded in South Dakota

12 records mapped · zoom and drag to explore

12 South Dakota records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Black Hills National Forest 1

Protected places with the most western deer mouse sightings, from the USGS Protected Areas Database plus named mountain ranges, good spots to look, not a full breakdown, so they don't sum to the total.

Where it's recorded in South Dakota

CountyRecords
Pennington County 5
Minnehaha County 3
Lawrence County 1
Hand County 1
Brown County 1
Brookings County 1

The complete county distribution, spread across 6 South Dakota counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Western deer mice carry no NatureServe state rank in South Dakota, and all 9 of the state’s records come from iNaturalist with no GBIF specimen data, meaning what’s documented here traces entirely to casual sightings of a small, nocturnal rodent that’s usually caught rather than photographed elsewhere.

Records scatter thin across six months with no single dominant peak, April, October, and December each carrying 2 sightings, too sparse a pattern in a dataset this small to describe any real seasonal trend beyond confirming the species turns up occasionally in Black Hills forest habitat.

Occurrence data from iNaturalist.

Western deer mouse sheltering in a rock crevice
Full species profile Western Deer Mouse Peromyscus sonoriensis Size 12–20 cm4.7–7.9 in Weight 15–32 g0.5–1.1 oz Lifespan 1 yr View the full profile

More mammals in South Dakota 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"