Montana’s American water shrew records follow cold, clean water, with reports concentrated near Flathead Lake and the wetlands of Red Rock Lakes National Wildlife Refuge, both places with the fast, oxygen-rich streams this diving shrew needs to hunt aquatic insect larvae. All 210 Montana records come from GBIF rather than iNaturalist, unsurprising for an animal that spends most of its short life underwater or under a stream bank rather than in view.
Reports peak sharply in July, with 69 of the 210 records, more than double the June count, tapering into August; that’s a summer fieldwork window, not a sign the shrew goes quiet the rest of the year, since it has to feed every few minutes around the clock regardless of season. Montana has no NatureServe subnational rank on file for this species, so its status here rests on federal nonindigenous-species data confirming it’s native rather than a formal state-level rank.
Full species profile
