The Great Basin pocket mouse is the largest member of the genus in Oregon. The dorsal pelage of this mouse is pinkish buff or ocherous buff overlain with black hairs; the venter is white to buffy. A lateral line, usually somewhat olive colored, separates the dorsal and ventral pelages. The tail is distinctly bicolored.

In Oregon, it occurs thought east of the Cascade Range, except it does not occur in the Wallowa and Blue mountains.

The Great Basin pocket mouse constructs burrows below the surface that contain granaries for storage of food, a nest cavity, and several entrances. They spend much of their lives in their burrows; even during the active season they usually are above ground only late in the evening or at night.