Willow Park, located in Johnson County, Wyoming, is a privately owned earth dam constructed in 1959 for irrigation purposes. This dam spans 860 feet in length and stands at a height of 60 feet, with a storage capacity of 6,469 acre-feet. Situated on the South Fork of South Piney Creek, Willow Park serves multiple functions including fire protection, stock watering, and recreational activities in addition to its primary role in irrigation.

Managed by the State Engineer's Office in Wyoming, Willow Park has been deemed a high hazard potential dam with a moderate risk assessment score of 3. The dam features a single slide gate outlet and an uncontrolled spillway with a width of 5 feet. Regular inspections are conducted, with the last assessment occurring in August 2017. Despite its age, Willow Park remains a vital resource for water management in the region, supporting agriculture and other water-related activities while also serving as an important structure for climate and water resource enthusiasts to study and monitor.