This article examines the interaction between geographic scale and ways of knowing in the context of collaborative stakeholder participation in ecosystem analysis and management. The examination uses data from a qualitative comparative case study of two watershed councils in western Oregon. The results tentatively support the proposition that geographic scale can significantly affect individual stakeholder ways of knowing. For small-scale places, stakeholder ways of knowing tend to be particularistic and rely on diverse personal experiences and specific place features; for large-scale places, stakeholder ways of knowing tend to be aesthetic and rely primarily on recreational experiences and scientific analyses. However, the results also indicate that geographic scale combines with at least three factors to affect the development of shared ways of knowing: (1) tensions between experts and laypersons; (2) primacy of organizational representation in stakeholder interactions; and (3) discovery of common group identity based on long-term communication and shared on-the-ground experiences, such as field trips. This examination suggests that geographic scale in ecosystem management is likely an important factor affecting working relationships in a collaborative stakeholder participation process. These relationships, in turn, can affect the perceived credibility and legitimacy of outcomes. FOR. SCI. 49(6):841–854.