A research study that began in 2012 confirmed Sierra Nevada red fox presence in the Oregon Cascades, specifically in the Mt. Jefferson, Mt. Washington, and Three Sisters Wilderness Areas. Confirmation was through genetic testing of hair and scat samples.

Sierra Nevada red fox is a subspecies of Red fox that live in high elevations. They are slightly darker than Red fox and are highly specialized to montane (mountain) ecosystems. 

In the red color phase, the upper body is reddish-brown with white chin, cheeks, throat and belly. This fox ranges from silver to black in the black/silver color phase with silver guard hairs appearing frosted. The cross phase shows characteristics of both red and black/silver.

The Sierra Nevada red fox is an Oregon Conservation Strategy Species in the East and West Cascades egoregions and the Klamath Mountains ecoregion.