Oregon mammals

Western Deer Mouse in Oregon

Peromyscus sonoriensis

Native to Oregon

Not listed as nonindigenous in Oregon by USGS NAS; treated as native to its mapped Oregon 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 Oregon, by the numbers

Common in Oregon 33rd most recorded of 133 mammals logged in Oregon

552 occurrence records
533 with iNaturalist photos
Jul 11, 2026 Last seen in Oregon

Records from 2000–2026.

552 total records count every Oregon occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 300; the monthly chart covers the 551 records with a full observation date.

When to look for the Western Deer Mouse in Oregon

Most sightings fall in June to October.

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

Monthly Oregon records (table)
MonthRecords
January21
February29
March33
April44
May42
June71
July69
August47
September62
October64
November34
December35

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

Seasonality

Year-round in Oregon, with recorded sightings peaking in June–October, with a smaller rise in April.

Occurrence map

Where Western Deer Mouse has been recorded in Oregon

300 records mapped · zoom and drag to explore

300 Oregon records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Mt. Hood National Forest 6
McDonald-Dunn Research Forest 6
Columbia River Gorge National Scenic Area 2
Cascade Range 2
E.E. Wilson Wildlife Area 2
Mount Jefferson Wilderness 2
Siuslaw National Forest 2
Lewis and Clark National Historical Park 2

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 Oregon

CountyRecords
Multnomah County 107
Deschutes County 51
Benton County 44
Lane County 43
Washington County 40
Clackamas County 37
Clatsop County 36
Lincoln County 21
Linn County 18
Coos County 15
Jefferson County 14
Harney County 12
22 other counties 114

The complete county distribution, spread across 34 Oregon counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Western deer-mouse records in Oregon are prominent along the Cascades, including Mount Hood and Willamette national forests and sites labeled to the range itself. June and July form the main summer crest, while October adds a distinct second rise instead of a simple warm-season decline. The monthly and place totals reflect documented specimens and sightings, not the abundance of this easily overlooked small mammal.

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 Oregon 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"