The canyon mouse is a moderate to small-sized mouse-like rodent with a long tail, nearly naked ears and a long, lax, and silky dusty gray pelage.

In Oregon, most locations where the canyon mouse has been found are in Harney and Malheur counties, but the distribution includes a group of localities in Crook, Jefferson, Wasco, and Wheeler counties and another group in Lake County. There are also records of the species in extreme southeastern Baker County. Rock, primarily rimrock and talus slopes, seems to be the key component of habitats occupied by the canyon mouse.

They are usually active nocturnally and are active throughout the year. Canyon mice are unusually agile. They carry their long tails arched over their backs, commonly squeeze into narrow crevices, and frequently make jumps as long as 20 cm.