Olympic shrew

Sorex rohweri

LCLeast Concern

The Olympic shrew is a little-known shrew of the Pacific Northwest lowlands, described as a distinct species only in recent decades and still recorded from a modest scatter of sites. Most records come from Washington's Olympic Peninsula and nearby lowlands, with a surprising outpost across the border in a British Columbia bog. It is exactly the kind of small mammal that careful trapping keeps revealing.

Range through the year

Where Olympic shrew is seen

Olympic shrew is recorded in 1 US state from 15 occurrence records, most heavily in Washington (15 records).

Current range15 records · 1 states
AlabamaArizonaArkansasCaliforniaColoradoConnecticutDelawareDistrict of ColumbiaFloridaGeorgiaIdahoIllinoisIndianaIowaKansasKentuckyLouisianaMaineMarylandMassachusettsMichiganMinnesotaMississippiMissouriMontanaNebraskaNevadaNew HampshireNew JerseyNew MexicoNew YorkNorth CarolinaNorth DakotaOhioOklahomaOregonPennsylvaniaRhode IslandSouth CarolinaSouth DakotaTennesseeTexasUtahVermontVirginiaWashington · 15 records · view state pageWest VirginiaWisconsinWyomingAlaskaAKHawaiiHIPuerto RicoPR
Occurrence data by state and month
Olympic shrew – occurrence records by US state and month (15 total across 1 states)
StateJanFebMarAprMayJunJulAugSepOctNovDecYear
Washington···212424···15

Based on 233 georeferenced US records, 2000-2026. Shading is observation density (where people record sightings), not true abundance. Alaska, Hawaii & Puerto Rico shown as insets.

Explore by state

Olympic shrew across 1 state

Occurrence records, conservation status, and the places it turns up, state by state. Open a state for detail, or visit its full page.

  • WashingtonNativeOccasional233 records

    State rankUnranked

    Notable placesMount Rainier National Park · Washington State Department of Natural Resources (WADNR) State Resource Management Area · Daniel J. Evans Wilderness Area · Ross Lake National Recreation Area

    Countiesrecorded in 12

    Year-round in Washington, with recorded sightings peaking in July.

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.

SizeOlympic shrew beside a 1.8 m adult, drawn to scale
Created by potrace 1.16, written by Peter Selinger 2001-2019 Created by potrace 1.16, written by Peter Selinger 2001-2019
Body length
10–12 cm4 in–5 in
Weight
5–9 g0.2–0.3 oz

Silhouettes drawn to scale against a 1.8 m5 ft 11 in adult.

Elevation

From 200 georeferenced records, the Olympic shrew is recorded from sea levelsea level to 1,018 m3,340 ft, with half of sightings below 148 m486 ft.

Each band shows the share of georeferenced sightings that fall within it. Records cluster where people live and hike, so low, populated elevations are over-represented. Read this as observation density, not true abundance.

Best encounter

Where and when to see an Olympic shrew

Your best chance: Washington.

Where
WashingtonWA

A shrew the books nearly missed

Shrew taxonomy rewards patience, and this species is proof. The animals now called Olympic shrews were long folded into the widespread masked shrew group, and only detailed work on skulls and chromosomes pulled them out as their own species. It is a mid-sized shrew, a few inches long with the tail, brownish above and paler below, and honestly not separable from its close relatives by a quick look in the hand. Range and lab work do what the eye cannot.

For a general reader the lesson is simple. A shrew caught in a wet thicket on the Olympic Peninsula may be this species, but confirming it takes an expert. That difficulty is why the record set is thin: not necessarily rarity, but the cost of being sure.

Wet thickets and bog edges

Where it has been found, the Olympic shrew keeps to moist cover: streamside thickets, damp forest edges, and marshy ground in the coastal lowlands. The famous outlier is Burns Bog near Vancouver, a huge domed peat bog where the species turned up well north of its known Washington sites. That discovery hints at a shrew more widespread than the record shows, hiding in wet pockets that mammalogists rarely trap.

Seasonal reports are few, and reading much into them would be a mistake. A handful of survey records can’t chart an animal’s year. What they do show is persistence: the species keeps turning up in the same kind of wet, brushy places across decades of scattered effort.

Recently described, still being mapped

The Olympic shrew carries the name rohweri and was recognized only in the twenty-first century’s wave of shrew revisions. Its conservation listing is Least Concern, but that rating leans on how little is known rather than on abundant evidence. A species recorded from a small number of sites earns attention automatically, and state biologists treat its Washington sites as worth watching.

The records below should be read as a map of effort and certainty, not a map of abundance. Each dot marks a place where someone set traps in the right wet thicket and identified the catch carefully. The gaps between dots are mostly unexamined ground, and the coming years of small-mammal survey work will likely fill some of them in.

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
  • PhyloPicCC0 / CC-BY per itemthe to-scale silhouettesBecky Barnes (Sorex) · Andrew A. Farke (human silhouette, CC-BY 3.0)
  • IUCN Red Listattributed factthe global conservation status