The following forms of Chipmunks are found in Yellowstone Park:
Buff-bellied Chipmunk—Eutamias amoenus luteiventris
This is the abundant little striped chipmunk seen throughout most of the park along the roads and trails and around camp sites. Upper parts with five dark and four light longitudinal stripes from shoulder to base of tail. Median stripe from crown to root of tail. Whitish stripes bordered by dark, above and below eye. Underparts buffy; color rich; 8½ inches over-all length.
Uinta Chipmunk—Eutamias umbrinus
Generally scattered over the park but not as common as the above. Larger in size, 10 inches over-all length; under parts whitish and stripes not as conspicuous as in the Buff-bellied.
Wasatch Chipmunk—Eutamias minimus consobrinus
These little chipmunks were reported by Bailey to be found near Yellowstone Lake and near the eastern and southern boundaries of the park in high, open valleys. They are hard to distinguish from the buff-bellied chipmunk, as their white belly is somewhat concealed. They are slightly smaller in size. A gray form of this species has been reported from Swan Lake Flat but it is probably rare.
PINE SQUIRREL
Wind River Mountains Red Squirrel, or Chickaree
Tamiasciurus hudsonicus ventorum
These little animals are abundant throughout the forested sections of the park. Lively and noisy, they immediately give voice to a tirade of scolding and chattering at the approach of an outsider to their domain.
