The Decorah Upper Milldam, located on the Upper Iowa River in Iowa, was completed in 1911 and serves as a recreational destination for water resource and climate enthusiasts. This gravity dam stands at a height of 8 feet and has a length of 300 feet, creating a surface area of 70 acres and providing a storage capacity of 358 acre-feet. The dam is state-regulated by the Iowa Department of Natural Resources and undergoes regular inspections to ensure its safety and functionality.

Despite being rated as having a low hazard potential, the Decorah Upper Milldam is considered to have a moderate risk level due to its age and condition assessment as "Not Rated." The spillway of the dam is uncontrolled with a width of 142 feet, allowing for controlled releases of excess water during periods of high flow. While the dam does not have outlet gates or associated structures, it continues to provide valuable recreational opportunities for the surrounding community and visitors alike.

As the Decorah Upper Milldam remains a prominent feature along the Upper Iowa River, it is important for water resource and climate enthusiasts to appreciate its historical significance and ongoing role in providing recreational benefits. With its scenic location and regulated state oversight, the dam serves as a reminder of the balance between human development and natural ecosystems in the management of water resources.