Utilizing a sequential explanatory mixed methods study design, this investigation assessed whether knowledge and skills acquired through the use of an experientially-based 4-H science curriculum that included a service-learning component helped participating 4-H youth develop the information, means, and opportunities to implement an authentic service-learning project related to the curriculum’s subject matter of predation and depredation. The study drew upon quantitative and qualitative data from outcome testing with participating 4-H youth from a county in Northern California. Results from pre-/post-surveys, retrospective surveys, a focus group, and individual and pair interviews showed an increase in 4-H participants’ content knowledge and skills, and in their ability to apply learned material to authentic contexts. This was evident in real-world contexts through improved animal husbandry methods on their home premises, an informational video they developed as part of a service-learning project, and the demonstration of their knowledge by sharing the video with the broader community. In addition, participants provided specific feedback on the constructivist-based curriculum activities that aided most in their content knowledge acquisition and the service-learning project. This study can serve as a model for the intentional incorporation of constructivist-based methods and service-learning in future 4-H curricula. It also contributes to service-learning research, particularly in non-formal settings with youth audiences, which has been limited.