Gaining access to early childhood education can be challenging for some families, but summer programs may provide more opportunities for children of all backgrounds. In the USA, some of these expanded opportunities have come by way of an increased number of nature-based preschool programs. This study investigated a short-term, nature-based summer preschool program. Using an ecological systems perspective, researchers determined how the program affected children’s social-emotional skills, if children from the program demonstrated appropriate academic growth, and if children showed stronger connections to nature after participation. Multiple data streams were analyzed using a mixed methods approach, including data from observation instruments, literacy skills tests, surveys, and caregiver interviews. Findings from 69 preschoolers and 15 caregivers indicated positive increases in children’s social-emotional skills, appropriate academic development, no significant changes in connections to nature, and caregivers who felt the program positively contributed to readiness. However, it is also clear from this study that additional research is needed on these kinds of preschool programs to determine the specific factors contributing to positive outcomes. (author abstract)