California mammals

Muskrat in California

Ondatra zibethicus

Native to California SNR Unranked in California

Native to California (NatureServe); USGS NAS also lists 1 out-of-range or translocated occurrence here.

IUCN Red List status

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

LC – Least Concern

Widespread and abundant; not at risk.

Muskrat in California, by the numbers

Common in California 60th most recorded of 233 mammals logged in California

925 occurrence records
917 with iNaturalist photos

Records from 2000–2026.

925 total records count every California occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 300; the monthly chart covers the 887 records with a full observation date.

When to look for the Muskrat in California

Most sightings fall in March to June.

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

Monthly California records (table)
MonthRecords
January58
February65
March125
April143
May120
June107
July79
August54
September35
October35
November36
December30

Monthly muskrat occurrence records (iNaturalist and GBIF) in California, 2000–2026.

Seasonality

Year-round in California, with recorded sightings peaking in March–June.

Occurrence map

Where Muskrat has been recorded in California

300 records mapped · zoom and drag to explore

300 California records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Yolo Bypass Wildlife Area 22
Oceano Dunes State Vehicular Recreation Area 14
Pismo State Beach 12
Tahoe National Forest 7
Lake Tahoe 5
Point Reyes National Seashore 4
Eldorado National Forest 3
McGrath State Beach 3

Protected places with the most muskrat 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 California

CountyRecords
Santa Clara County 131
Alameda County 84
Sacramento County 66
Yolo County 55
Marin County 50
Shasta County 40
Santa Cruz County 36
Imperial County 36
Ventura County 33
San Luis Obispo County 32
Siskiyou County 29
Placer County 28
27 other counties 305

The complete county distribution, spread across 39 California counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Muskrat reports follow California’s marshes, ponds, canals, and slow waterways rather than the dry land between them. Klamath Basin, Don Edwards San Francisco Bay, and the Salton Sea each offer wetland habitat, but their cold winters, tidal marshes, and desert heat create very different conditions.

Records rise from March through June, with the clearest high in April, then fall sharply in late summer. Spring vegetation and more time above water may aid detection. Muskrats are native to parts of California and were introduced to others, and either way the report clusters mark accessible banks and watched refuges rather than population size.

Occurrence data from iNaturalist and GBIF.

Muskrat in other states

Muskrat range map (all states)

More mammals in California 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
  • NatureServe ExplorerCC-BYthe state conservation rank
  • 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"