This study explored how family-based nature activities (FBNA) change in frequency and activity type over time across five developmental periods (early childhood [EC], middle childhood [MC], early adolescence [E-ADOL], middle adolescence [M-ADOL], and emerging adulthood [EA]) and whether these early experiences are associated with adulthood outdoor participation and preferences. Retrospective online questionnaires were collected from 349 undergraduate students. Results showed that FBNA declined in frequency across the early life course, and that White students reported the greatest frequency of FBNA. Activities shifted from engagement in local parks and informal play in early and MC to more physical and social activities in EA. Males engaged in more sports whereas use of local parks, physical, and water-based FBNA were more common among females. Frequency of participation in FBNA across the early life course (especially during M-ADOL) was associated with a greater frequency of time spent outside and a preference for outdoor environments in EA.