Mcmillen Dam, located in Cheyenne, Nebraska, near the city of Sidney, serves multiple purposes including fire protection, stock, and small fish pond management. This privately owned earth dam, completed in 1960, stands at a height of 16 feet and stretches 735 feet in length. With a storage capacity of 113.5 acre-feet and a surface area of 12.3 acres, the dam plays a crucial role in water resource management in the region.

Managed by the Nebraska Department of Natural Resources, Mcmillen Dam is regulated, inspected, and enforced by state authorities to ensure its structural integrity and safety. Despite having a low hazard potential, the dam's condition assessment in 2018 was deemed unsatisfactory, prompting regular inspections every five years. The dam's ability to control drainage and maintain water levels in the TR-Sidney Draw stream highlights its significance in mitigating potential flood risks and providing a sustainable water source for the local ecosystem.

As a part of the Omaha District and under the jurisdiction of Congressional District 03, Nebraska, Mcmillen Dam stands as a testament to the intersection of human engineering and natural resource management. With its historical relevance and ongoing maintenance, the dam symbolizes the delicate balance between harnessing water resources for human needs while safeguarding the environment and surrounding communities from potential risks associated with climate change and water scarcity.