Illinois mammals

Muskrat in Illinois

Ondatra zibethicus

Native to Illinois S5 Secure in Illinois

Not listed as nonindigenous in Illinois by USGS NAS; native to its Illinois range.

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.

Muskrats resting on a floating log in open waterMuskrat swimming head-on through calm waterLive muskrat sitting on a grassy bank at the water edgeTwo muskrats at a grassy water edgeMuskrat swimming with a long narrow tail trailing behind
Photo: Ken Clark · CC-BYMuskrats resting on a floating log in open waterPhoto: Svetlana Tsarakhova · CC0Muskrat swimming head-on through calm waterPhoto: Robert McLeod · CC0Live muskrat sitting on a grassy bank at the water edgePhoto: Dan Vickers · CC-BYTwo muskrats at a grassy water edgePhoto: Lukas Zangl · CC-BYMuskrat swimming with a long narrow tail trailing behind

Muskrat in Illinois, by the numbers

Common in Illinois 9th most recorded of 80 mammals logged in Illinois

2,049 occurrence records
1,952 with iNaturalist photos
Jul 6, 2026 Last seen in Illinois

Records from 2000–2026.

2,049 total records count every Illinois occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 300; the monthly chart covers the 2,032 records with a full observation date.

When to look for the Muskrat in Illinois

Most sightings fall in March to May.

2,032 Illinois occurrence records (iNaturalist and GBIF) by month of year, 2000–2026. Shows when the species is recorded, not a guarantee of presence.

Monthly Illinois records (table)
MonthRecords
January65
February91
March326
April383
May356
June202
July156
August114
September76
October73
November94
December96

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

Seasonality

Year-round in Illinois, with recorded sightings peaking in March–May.

Occurrence map

Where Muskrat has been recorded in Illinois

300 records mapped · zoom and drag to explore

299 Illinois records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Illinois and Michigan Canal State Trail 19
Adeline Jay Geo-Karis Illinois Beach State Park 17
Volo Bog State Natural Area 13
William W. Powers State Recreation Area 10
Rock Cut State Park 9
Moraine Hills State Park 7
Larue-Pine Hills National Natural Landmark 6
Horseshoe Lake-Madison State Park 6

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 Illinois

CountyRecords
Cook County 648
DuPage County 328
Lake County 216
Kane County 113
Will County 108
Champaign County 96
Winnebago County 86
McHenry County 67
DeKalb County 26
McLean County 23
Madison County 23
Lake Michigan County 20
53 other counties 295

The complete county distribution, spread across 65 Illinois counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

The Des Plaines River corridor and wet portions of Cook County preserves give muskrat reports a strong northeastern Illinois setting. Midewin adds restored ponds and marshy ground amid open prairie, showing that suitable water can matter more than whether the surrounding landscape is urban or rural.

Reports cover every month and crest in April. Thinner shoreline plants and increased spring field activity can expose more animals to view, so the curve measures reporting rather than muskrat abundance.

Muskrat in other states

Muskrats resting on a floating log in open water
Full species profile Muskrat Ondatra zibethicus Size 25–36 cm9.8–14.2 in Weight 0.6–2 kg1.3–4.4 lb Lifespan 3 yr View the full profile

More mammals in Illinois 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"