"Parknerships" (park partnerships) are an innovative means of enhancing people's connections with conserved spaces and stories, drawing on the combined strengths of multiple organizations. As a specific type of collaboration, a parknership is focused among parks-related organizations sharing common goals of building positive experiences for individuals, the community, and the environment. The need for parknerships is heightened in complex settings like urban areas, and with national organizations concerned with local relevance, such as the National Park Service (NPS). Although parknerships have emerged as a crucial mode of local connection and are increasingly highlighted in park guidance, scant information exists on what mechanisms contribute to their long-term, multi-effort success. We seek to address this by investigating what elements contribute to a sustainable and successful parknership. To frame this inquiry, we drew from the concept of relevance and framework of collective impact. Using semi-structured interviews (n = 14) with NPS and partners in the San Francisco Bay Area (an urban area with rich cultural diversity and long environmental history), we elicited understanding of sustainable parknerships. Participants emphasized the importance of the parknerships' context, process, and goal. Consideration of these intersectional themes may be critical to sustainable, relevance-related collaborations among parknerships.