Using a sociocultural framework to approach intergenerational learning, this inquiry examines learning processes used by families during visits to one nature center. Data were collected from videotaped observations of families participating in an environmental education program and a follow-up task to draw the habitat of raptors. Based on a thematic analysis, researchers developed two themes about the learning processes at play in the nature center, related to the use of prior knowledge. First, families' prior knowledge used at the nature center came from informal education activities: (a) observation in the outdoors and spaces designed to represent an aspect of nature, (b) media (including books and Internet), and (c) experiences at informal education institutions. Second, when sharing prior knowledge, participation frameworks were created through the conversation that leveled the hierarchy between parent and child allowing for negotiation and collaborative idea formation. In the nature center, families valued social harmony by positioning their children as capable contributors of environmental knowledge. Suggestions to researchers taking a sociocultural approach are given, including the potential of 'participation frameworks' as an analytical tool to study learning interactions and as a potential tool for environmental educators to encourage families to create roles and structures for successful learning outcomes in nature centers.