The Cascade red-backed mouse is found in the Cascade Mountains from British Columbia southward into Washington, east into northern Idaho and northeastern Oregon. In Mount Rainier National Park it occurs generally from park boundaries to forest line.
The heavily wooded areas of the park are the preferred habitats of the red-backs. They are usually common in such localities, but are not locally abundant in colonies, as are the field mice.
The activities of these mice are not confined to nocturnal excursions. They may be seen at any time of day, and the quiet observer in the deep woods is almost certain to glimpse them if he is patient enough to watch for a few moments.
NORTHWESTERN JUMPING MOUSE
Zapus princeps trinotatus Rhoads
The Northwestern jumping mouse is a little larger than a house mouse, head and body about four inches, tail about six inches. The back is dark, sprinkled with buff; a broad band of buff, sprinkled with blackish hairs, extends along the sides; the underparts are pure white. The long tail is dull gray above, white below, and almost naked except for a tiny tuft of dark hair at the tip. This mouse may be easily distinguished from any other park animal by the long hind legs and tail.
Specimens in park collection: RNP-6, RNP-24, RNP-25, RNP-52, RNP-53, RNP-54, RNP-58, RNP-73, RNP-76, RNP-92; Longmire Museum, Park Headquarters.
The jumping mice are found throughout most of the United States from northern California and North Carolina, northward into Canada to the Arctic Circle. The Northwestern jumping mouse occurs from northern California through the Cascades to the coastal region of southern British Columbia.
In Mount Rainier National Park this animal is found irregularly from park boundaries to 6,000 feet. It is not common and is rarely seen.
The usual habitats of the jumping mice are the subalpine parks and meadows, where they may sometimes be abundant in a restricted locality. They hibernate from early fall until late spring, and during their period of summer activity they rarely leave the nest during daylight hours. The nests are on the ground, small and dome-shaped, made of dried grasses.