Using an interdisciplinary approach to water resource education, 4-H Youth Development and Environmental Extension agents enlisted 4-H teens to connect local watershed education with social action. Teens participated in a dynamic service learning project that included learning about nonpoint source pollution; constructing, decorating, and teaching families about rain barrels; and selling the barrels at the county fair. The program resulted in significant knowledge increase among the teens. Furthermore, rain barrel installation rates were higher than the average rates of similar Extension programs. This program, while small in scale, illustrates the potential of employing teens as teachers in interdisciplinary Extension programs.