The dusky shrew can be found throughout Vancouver Island, with its range stretching from Alaska to Mexico. It lives in a wide variety of habitats, including grasslands, damp meadows, swamps, and along rivers & streams.
It is most common in areas of dense cover, and least seen in open expanses.
Adults of this species can reach lengths of 108 mm. Males weigh up to 5.5 g, with females being a bit larger, reaching weights of about 6.5 g.
They were at one time thought to be a subspecies of the vagrant shrew, but are now considered to be a species all of its own.
They are larger and paler than the vagrant shrew.