Climate adaptation is a process for minimizing the risks of damage or loss to coastal archaeological sites. Yet, adaptation requires identifying and prioritizing among the diverse aspects of a site's significance, as not all sites can be simultaneously adapted due to financial and human capital constraints. Developing a measurement framework that can ascertain the relative significance between sites necessitates the collaboration of multiple perspectives, including experts who set policy and on-the-ground managers who must translate policy into practice while accounting for the management preferences of associated communities. This paper explores if a values-based process enables co-production of knowledge related to the significance of archeological sites. Specifically, this paper examines the influences of a workshop-conducted with diverse archaeological experts working for the U.S. National Park Service-on knowledge co-production and documents the extent of changes in experts' opinions using a pre-post survey design. Findings suggest that the values-based approach applied during the workshop can have a positive impact on knowledge co-production among experts. Changes were found in experts' perceptions of the importance of various considerations influencing archaeological site prioritization, as well as of the extent to which uncertainties challenge archaeological preservation. This paper presents novel findings about the importance of knowledge co-production in relation to coastal archaeological site preservation and climate adaptation in the U.S. Prioritization considerations and challenges of various uncertainties assessed in this study can provide valuable insights for progress in climate change policy for cultural heritage both in the U.S and globally.