Using families as the analytical focus, this study informs the field of informal science education with a focus on the role of prior experiences in family science conversations during nature walks at an outdoor-based nature center. Through video-based research, the team analyzed 16 families during walks at a nature center. Each family's prior science learning experience provided conversational strategies for learning together as a social group and when making meaning out of observations in the outdoors. This analysis provides three main findings: (1) families frequently tapped into a vast repertoire of previous experiences during conversations about nature and very often, explicitly sourced a specific prior experience in their dialogue with one another; (2) when families sourced a prior experience, they almost exclusively named an experience from a nonschool setting, with everyday experiences, designed spaces (i.e., informal institutions), and programs for science learning being the most common experiences cited; and (3) families leveraged references to prior experiences during family science conversations to serve four primary facilitation processes in conversation: reminding, prompting, explaining, and orienting. Implications from this study emphasize the importance of referencing previous life experiences during family science conversations as a meaning-making tool and for additional research on families learning science in outdoor education spaces.