The Sonoma tree vole is arboreal and associated with mature forests. It has a reddish-brown back, gray and rusty tones underneath, and a thick, furred tail.
Its back is reddish brown, while the underside is gray with rusty-brown hairs. The tail is thick and well furred, and the ears are small and almost hairless.
It is an arboreal mammal associated with mature forest. In a Forest Service study, nests were found most often in unharvested or partly harvested old-growth Douglas-fir stands.
An extinction-risk assessment has not been added yet.