Preble's shrew is the smallest shrew in Oregon; adults commonly weigh less than a dime. The pelage is medium dark-brown to very dark-gray on the dorsum and silvery gray on the venter. The tail is bicolored, medium dark-brown on the dorsal surface, white on the ventral surface and darkening toward the tip.

In Oregon, it has been found in Deschutes, Grant, Klamath, Lake, Harney, Malheur, and Wallowa counties. Its habitats include marshes, along streams, dry bunchgrass, and wet, alkaline habitat. Grasses and sagebrush are common to most habitats.