North American Deermouse is the more formal name for what most people call the deer mouse, likely the single most widely distributed native rodent on the continent. Montana’s 663 mapped records for it come entirely from GBIF specimen data, not photo apps, since telling this species apart from its close cousins by eye alone is genuinely difficult.
The listed locations, Red Rock Lakes National Wildlife Refuge, Flathead Lake, and the Missouri River corridor, span wetland, lakeshore, and river-bottom terrain. That range mirrors the species’ own tolerance: it does not specialize in one type of ground, which is a large part of why it shows up almost everywhere researchers look.
July and August carry the heaviest count of records, by a wide margin over the rest of the year. Small-mammal field crews concentrate their trapping effort in those two months, so the summer spike says more about survey timing than about the mouse disappearing in winter.
Full species profile
