Understanding how stakeholders conceptualize the dynamic environmental systems they live within and act upon is essential for long-term sustainability planning. For shared resource systems where decision making is increasingly democratized, agencies engage stakeholders to document local understandings of physical processes useful for resource management. For a variety of fiscal, logistical, and policy reasons, most studies are snapshots in time with few agencies able to devote resources for longitudinal studies. Yet for large river systems that regularly change with floods, drought, and floodplain development cycles, one-off social studies are unable to respond to such human- environment dynamism. To explore longitudinal human-water dynamics in the Yellowstone River reach in Montana (US), this study uses interviews with 15 individuals interviewed in 2006, 2012, and 2018 field seasons. The Yellowstone River is the largest undammed river in the US. It is located in the arid Western United States, and experiences annual flooding from mountain snowmelt, regular drought cycles, increased water use from floodplain development, irrigation, and recreation. Interviewees had a history of involvement with the Yellowstone River decision making and/or were riverfront landowners each with the capacity to shape the physical features of this system. This study takes a scholarly approach to expressed participant concerns as empirical evidence that reflects the socio-hydrological phenomenon occurring in the Yellowstone River Valley. Analysis of stakeholder accounts of physical processes pay special attention to expressions of how they understand the physical processes (flood, drought, and erosion) and how they express it should be managed. The benefit of engaging the same stakeholders with the same questions in 2006, 2012, and 2018 affords attention to any patterns of change over time concerning stakeholders' descriptions of riverine processes. Ultimately, this study brings clarity to the place-based phenomenon taking place in t Yellowstone River through a longitudinal comparative analysis.