Warner No. 1 is a privately owned earth dam located in Douglas, Wyoming, along the North Five Mile Creek. Completed in 1951, this dam serves primarily for irrigation purposes, with a storage capacity of 362 acre-feet and a surface area of 34 acres. Standing at a height of 17 feet with a spillway width of 75 feet, Warner No. 1 has a low hazard potential and is rated as having a moderate risk level.

Despite being privately owned, Warner No. 1 is regulated by the State of Wyoming, with inspection, permitting, and enforcement conducted by the State Engineer's Office. The dam's condition is currently not rated, and the last inspection took place in June 2019. With a slide gate as its outlet structure, Warner No. 1 is designed to provide fire protection, support stock, and serve as a small fish pond in addition to its main irrigation function.

Located within Congressional District 00 in Wyoming, Warner No. 1 is a vital water resource infrastructure that contributes to the management of water resources in the region. With its historical significance and ongoing role in supporting agricultural activities, this dam showcases the intersection of water resource management and climate resilience in the state.