Background: Schools provide an ideal setting for promoting healthy lifestyles in youth, but it has proven difficult to promote the adoption and implementation of evidence-based programming by school leaders. The SWITCH® ("School Wellness Integration Targeting Child Health") intervention is a capacity-building process designed to help school leaders learn how to plan, implement, and sustain school wellness programs on their own. Objective: The present study evaluates the transdisciplinary approaches used in establishing an integrated research-practice partnership with the state-wide 4-H/Extension network to support broader dissemination. Method: The study used a mixed methods approach to evaluate the degree of engagement and motivation of 4-H leaders (N = 30) for providing ancillary support for local school wellness programming. Engagement from 4-H Staff was logged over a year-long period through tracking completion of training and ongoing engagement with aspects of SWITCH. They completed checkpoint surveys and an interview to provide perceptions of supporting school implementation of SWITCH programming. Data were analysed through Pearson bivariate correlations and constant comparative analysis. Results: County-level 4-H staff demonstrated high engagement in SWITCH by attending training sessions and hosting structured checkpoint sessions with schools. Interview data revealed that 4-H Staff valued connections with schools and emphasized that training on SWITCH was consistent with their existing roles related to youth programming. Conclusions The results demonstrate the value of the sequential capacity-building process used to train 4-H Staff to facilitate school wellness programming. The transdisciplinary approaches built transferable skills and fostered relationships that directly support the broader goals of 4-H.