Montana’s arctic shrew file is thin: 13 records since 2000, and every one comes from the far northeastern corner of the state, in Sheridan (9) and Roosevelt (4) counties along the Canadian line. That’s prairie country, not the high mountain valleys people picture for a boreal shrew, and it suggests the species reaches Montana from the north, spilling down out of Canada into the state’s coolest, wettest corners.
It’s worth being honest about what this doesn’t show. Glacier National Park and the Custer-Gallatin backcountry hold plenty of suitable-looking habitat, and the absence of records there likely reflects how rarely anyone traps or identifies shrews, not a true gap in the range. All of the Montana reports fall between June and September, which is survey season, and NatureServe calls the species unrankable in the state for lack of information. Montana’s picture of this animal is a pencil sketch, and every verified record from outside those two counties would sharpen it.
Full species profile
