American pikas in the Sierra Nevada and Great Basin (Ochotona princeps schisticeps) are facing population declines and losses at an unprecedented rate. While much of this may be attributed to climate change-related impacts, the role of competition with other mammals that reside in and near pika habitat has not been thoroughly addressed. We present a multi-species diet study-in-progress, using DNA metabarcoding of fecal samples collected within and in the immediate vicinity of pika habitat in the White Mountains of southeastern California and Lassen Volcanic National Park in northeastern California. We will 1) characterize summer diet of ten species, with a focus on marmots (Marmota flaviventris), chipmunks (Neotamias sp.), and leporids (Lepus and Sylvilagus); and 2) assess the degree of dietary overlap and/or niche partitioning among species. This study will add an understudied dimension to our understanding of the challenges faced by American pikas.