U S A, also known as Winkler Dam, is a federal-owned structure located in South Dakota along the TRIB MEDICINE KNOLL CREEK. Built in 1938, this earth dam stands at a height of 26 feet and stretches 690 feet in length, with a storage capacity of 624 acre-feet. Despite its low hazard potential, the dam has not been rated for its current condition.

Managed by the St. Paul District of the US Army Corps of Engineers, U S A serves as a crucial water resource for the region, providing irrigation and flood control benefits. With a maximum discharge capacity of 3,570 cubic feet per second, the dam plays a vital role in water management in Sully County, South Dakota. However, it is notable that the dam is not regulated by the state and does not have a formal inspection, enforcement, or permitting process in place.

Given its historical significance and importance for local water infrastructure, U S A represents a key piece of the region's water management system. As water resource and climate enthusiasts continue to monitor and advocate for sustainable water practices, understanding the role and condition of structures like U S A will be essential in ensuring the resilience and safety of water resources in South Dakota and beyond.