Montana’s 13 western water shrew records come from the mountain west and southwest, led by Missoula County with 6, with single records inside Yellowstone National Park and Bitterroot National Forest. That’s cold mountain-creek country, exactly the fast, clean water this diving shrew depends on.
The state logged 12 GBIF records and just 2 iNaturalist observations, in keeping with a shrew that’s genetically distinct from, but nearly identical in the field to, the American water shrew found farther east in Montana; the two overlap enough that geography does more identification work here than appearance. Reports peak in August with 6 records, too few to mark a true activity peak, and a metabolism this fast keeps the shrew hunting year-round. NatureServe rates the species Apparently Secure (S4) in Montana, a step below the Secure rank often seen in its more widespread relatives.
Full species profile
