Training interventions that target supervisors as a mechanism to initiate change in employee health, well-being, and work outcomes are increasingly common, but research has largely neglected to evaluate the impact that these interventions have on supervisors themselves. Relying on conservation of resources theory (Hobfoll 1989, 2001), this study sought to determine the effects that a supervisor-focused intervention had on supervisor and employee work, well-being, and safety outcomes. Participants included 192 U.S. Forest Service (USFS) workers (125 employees and 67 supervisors). Supervisors in the intervention group completed a computer-based training aimed at teaching behaviors that better support employees’ needs and subsequently tracked supportive behaviors for two weeks. Results showed that, for employees, the intervention led to significantly lower psychological distress and less concerns about forest safety. For supervisors, the intervention led to higher work-to-family conflict and lower organizational commitment. Furthermore, supervisor reports of job demands at baseline moderated the intervention’s effect on supervisor burnout, such that burnout was higher for those supervisors who reported lower job demands at baseline. Overall, consistent with previous research on supervisor training interventions, employees exhibited positive outcomes from the intervention. Detrimental effects of the intervention for supervisors may have been due to added responsibilities from participation in the training. Suggestions to mitigate potential detrimental effects of supervisor intervention participation are discussed.