Nine Eagles Park Lake Dam, located in Decatur County, Iowa, is a state-regulated earth dam completed in 1930 for the primary purpose of recreation. Standing at a height of 53 feet and stretching 1000 feet in length, this dam holds a maximum storage capacity of 1560 acre-feet and covers a surface area of 59 acres. Situated on the TR-Thompson River, the dam is under the jurisdiction of the Iowa Department of Natural Resources, ensuring regular inspections and enforcement of safety measures.

With a significant hazard potential and a fair condition assessment as of May 2017, Nine Eagles Park Lake Dam serves as a vital recreational resource in the region. The dam's uncontrolled spillway, with a width of 55 feet, helps manage water flow during high water events. Despite moderate risk assessment, the dam continues to provide opportunities for outdoor activities and water-based recreation in the area. As a beloved feature of the landscape, the dam's role in water resource management and climate resilience underscores its importance for both local communities and environmental enthusiasts alike.