The Sierra Nevada red fox (SNRF), Vulpes vulpes necator, is a high elevation subspecies that historically occurred throughout the Sierra Nevada and Cascade mountains of California and Oregon. Recently, the distinct population segment in the Sierra Nevada was listed as Endangered under the U. S. Endangered Species Act due to low population numbers and low genetic diversity. Despite this recent listing, little is known about basic SNRF ecology, including diet and its overlap with other mesocarnivores in their community. To help fill these gaps, we used DNA extracted from 924 mesocarnivore scats collected from the Sonora Pass region to better characterize the diets of sympatric SNRFs, coyotes, bobcats, and martens. We used metabarcoding whereby we performed multiplex PCR to amplify plant and vertebrate taxa from food items using primers from chloroplast (trnL) and mitochondrial (12SV5) regions, respectively. We analyzed data to assess what prey were likely of greatest importance to SNRFs during different seasons and used Pianka's niche overlap index to quantify diet overlap among SNRFs, coyotes, martens, and bobcats. Our results on key prey species, diet diversity, seasonal differences in diet, and dietary overlap with potential competitors will provide basic ecological understanding fundamental to recovery planning.