The Sierra Nevada red fox is a rare and endangered subspecies of red fox limited to upper montane forests, subalpine, and alpine environments of California and Oregon. Updated information on its contemporary distribution and density is needed to guide and evaluate conservation and management actions.
We combined 12 years (2009–2020) of detection and non-detection data collected throughout California and Oregon to model the potential distribution and density of Sierra Nevada red foxes throughout their historical and contemporary ranges. We estimated a density of approximately one fox per 100 km2 distributed throughout 22,926 km2 in three distinct regions of California and Oregon–Sierra Nevada, Lassen Peak, and Oregon Cascades. Sierra Nevada red foxes were most likely to be found in areas with low minimum temperatures and high snow water equivalent. Our results provided a contemporary baseline to inform the development and evaluation of conservation and management actions, and guide future survey efforts (Green et al. 2023).