The Lake Roosevelt Fisheries Evaluation Program was established to monitor and evaluate how hydropower operations affect water quality and fishery resources of Lake Roosevelt in northeastern Washington. Prior to the construction of the Grand Coulee Dam (1933–1941), the upper Columbia River supported salmon runs that were both culturally and nutritionally essential to Indigenous communities. The dam’s construction blocked salmon migration and inundated tribal lands, creating the reservoir now known as Lake Roosevelt. Operational impacts from Grand Coulee Dam alter flow regimes, water temperature, and turbidity, influencing ecosystem structure and function - from primary productivity to fish migration, survival, and reproduction. Working under Spokane Tribal Fisheries, the Limnology Team contributes to this tribal-led management effort by monitoring the lake’s baseline food-web dynamics and the abiotic conditions that shape habitat suitability and overall water quality. Our mission is to preserve, protect, and enhance the long-term sustainability of tribal fisheries for present and future generations who remain closely connected to this culturally significant waterbody. Here, we present the limnology component of this long-term monitoring program, highlighting multi-decadal data collection efforts and outlining directions for future research and adaptive management.