Wyoming’s file on the plains pocket mouse is one of the thinnest anywhere: 11 records spread across a quarter century, and 7 of those from Goshen County in the state’s southeast corner. That’s the North Platte lowland, where sandy shortgrass habitat reaches in from the Nebraska panhandle, and it’s about as far from Wyoming’s famous sagebrush basins as the state gets.
Records in the east, suggestions in the west
The viewing suggestions point to the Red Desert, Seedskadee National Wildlife Refuge, and the Green River corridor, all in the state’s dry southwest. The records themselves say otherwise: Albany and Carbon counties contribute 3 between them, and the southwest hasn’t produced a single one in this dataset. That gap doesn’t clear the southwest of the mouse. It means the habitat models see plausible ground where observers have barely looked, and a confirmed sighting from the Red Desert would matter more than a dozen more from Goshen County.
A short summer window
Every Wyoming record falls between July and November, with July and August carrying 9 of the 11. Some of that is biology, since pocket mice pass the deep winter in torpor and young animals only appear from midsummer on. Some of it is simply that few people survey small mammals on the high plains in the off-season. With a sample this small, one good field season could redraw the seasonal chart entirely.
Status in Wyoming
NatureServe ranks the species S2, imperiled, in Wyoming, a sharp step down from its secure global standing. The mouse is native here, living at the northwestern fringe of its range, and fringe populations are always the easiest to lose and the slowest to confirm. Eleven records can’t say how many mice Wyoming holds, only that the ones it does hold keep turning up in the same sandy corner.
Full species profile
