The sustainable management of coupled social-ecological systems, such as water resource systems, requires institutional mechanisms for managing uncertainties and building more resilient social-ecological systems. Adaptive governance is an outcome of the search for a way to manage uncertainties and complexities within social-ecological systems. The concept of adaptive governance has emerged as a product of resilience theory and theoretical insights on common pool resources management. Adaptive governance refers to flexible multi-level institutions that connect state and non-state actors to facilitate a collaborative and learning-based approach to ecosystem management. As such, it has the potential to integrate social considerations into the decision process while also dealing with uncertainties in complex water resource systems. However, little is understood on how transitions toward adaptive governance systems take place and what criteria qualify a given institutional mechanism as an adaptive governance regime. This thesis presents results on a study that was aimed at understanding the process and outcomes of transitions toward adaptive water governance by using the Cache River Joint Venture Partnership (CRWJVP) within the Cache River Watershed in Southern Illinois as a case study. Qualitative data for the study were generated through key informant interviews among members of the CRWJVP and other knowledgeable actors, document review, and participant observation. The results revealed that the transformation of the governance of the Cache River watershed through the emergence of the CRWJVP was the result of ecological crises that began a citizen-led effort to preserve the Cache River wetlands. Additionally, the transition process was facilitated through trust-building, incentives, leadership, enabling legislation, and the role of bridging organizations. The results also showed that when compared to the attributes of an adaptive governance system, the current governance system of the Cache River watershed does not fully exhibit all the ideal attributes. However, the CRWJVP is moving towards an adaptive governance regime through the recent utilization of decision-making processes for recognizing and managing conflicts and uncertainties in the management of the watershed. Barriers in the transition process and recommendations for overcoming them are also discussed in the thesis. In all, findings from this study should be of relevance to scientists and decision-makers interested in understanding and enhancing transitions toward adaptive governance for the sustainable management of land and water resources in the Cache River watershed and elsewhere.