Two kinds of chipmunks, the Cooper and Hollister, are known to occur within the park. Although their altitudinal ranges overlap, the two species may be quite readily distinguished by their variation in size and other characteristics. A brief discussion of each follows:
The Hollister chipmunk is a lively and audacious little animal.
The Cooper chipmunk, Tamias townsendii cooperi Baird, is the larger of the two species mentioned above. It is predominantly dark brown in color; the light colored stripes above and below the eye are indistinct; the black head stripes are not conspicuous; the nine alternating black and grayish white lengthwise stripes on the back are somewhat obscured by the dark color; the tail is black above, grizzled with white, silvery margined, reddish brown below. The total length of a typical specimen is ten inches; head and body, five and one-half inches, tail four and one-half inches.
This chipmunk is found in the higher eastern Cascade Mountains and Olympic Mountains of Washington. In Mount Rainier National Park it occurs from park boundaries to 6,000 feet, almost to forest line.
The Hollister chipmunk, Tamias amoenus ludibundus (Hollister), also called the little chipmunk or Alpine chipmunk, is about a third smaller in size than the Cooper chipmunk. It is predominantly gray brown in color. The light colored stripes above and below the eye are distinct; the black head stripes are more conspicuous than those of the Cooper, the back stripes are sharply defined; the tail is brown mixed with black above, margined with yellowish brown, yellowish brown below. The total length is about eight and three-fourths inches; head and body four and three-fourths inches, tail four inches.
The Hollister chipmunk is found in the higher Cascade Mountains of Washington. In Mount Rainier National Park it occurs generally in the Hudsonian Zone between 4,500 and 6,500 feet, rarely lower or above forest line, but it is one of the few park animals recorded on the summit of Mount Rainier.
Specimens in park collection: Cooper chipmunk, RNP-7, RNP-8, RNP-9, RNP-16, RNP-18, RNP-74, RNP-110; Hollister chipmunk, RNP-28, RNP-29, RNP-30, RNP-95; Longmire Museum, Park Headquarters.
The lively, audacious, and beautifully marked chipmunks are the most popular of all the animals of the park. Locally abundant as they are in the neighborhood of the campgrounds and lodges, easily observed because of their diurnal habits and lack of fear, they are a source of entertainment and amusement to many park visitors.
Like the mantled ground squirrels, the chipmunks adapt themselves rapidly to man’s presence, forage about camps and lodges in search of various delicacies, invade camp stores without hesitation, but are such engaging company that it is difficult to regard them as anything other than friendly guests.