Mountain lions are a widely distributed carnivore with larger home ranges and lower densities than most other co-occurring mammals. They are important because of their ecological role as a top predator and the often-contentious concerns about their conservation and management. Consequently, an ability to accurately and precisely estimate mountain lion population densities over large geographical regions is a critical need for wildlife agencies. We report on the first attempt to apply spatial capture recapture (SCR) modeling to extrapolate density estimation across the entirety of the species’ range (273,369 km2) in California. We applied SCR to fecal DNA surveys that identified 287 unique mountain lions from 13 large (mean =2,598 km2) study areas well distributed across the state during 2017–2022. After controlling for individual differences in space use and landscape-level variations in density, we estimated an average, overall statewide population of 3,238 lions (90%CI: 2,863–3,627) during this time period. On the one hand, these results suggest that SCR using fecal DNA can provide a non-invasive, practical, and cost-effective means of providing agencies the robust population estimates they need for effectively conserving and managing mountain lions and other wide-ranging species. On the other hand, our space use estimates from SCR were substantially lower than results from independently-collected GPS collar telemetry data (n=244 lions) suggesting that the statewide lion population could be ~42% larger than our estimate from SCR. Although we enumerate good reasons why space use estimates from these two sources may not be comparable, more research is crucial on how best to integrate telemetry into SCR models.