In California mountain lions (Puma concolor) are a specially protected species and the focus of a statewide program for population health, ecology, genetics, habitat connectivity and conflict reduction. We document early rewilding efforts for mountain lions by the California Department of Fish and Wildlife and its collaborators. Since 2016, mountain lion rewilding efforts have been carefully implemented on a case-by-case basis. Five attempts to reunite kittens with a dam or foster and 14 rehabilitation attempts of older kittens, subadults, or adults have been conducted. Of the five reunification attempts, two were deemed successful based on camera-trap detections. Mountain lions deemed rehabilitation candidates were carefully selected based on presenting problem, age and presentation, prognosis for full physical and behavioral function. Of 14 rehabilitation attempts, eleven were released, one died in care, one was euthanized due to extent of injuries, and one was deemed non-releasable and placed into captivity. All rehabilitated-released animals were fitted with GPS-tracking collars for monitoring post-release movements and survival. We discuss case outcomes, provisional selection criteria, rehabilitation collaborations, and considerations involved in large carnivore specialty rehabilitation. Active collaboration with partners involved in rewilding large native carnivores will help optimize efforts and outcomes for these unique cases.