Island Park, located in Idaho along the Henrys Fork River, is a federal-owned irrigation dam managed by the Bureau of Reclamation. Built in 1937, this earth dam stands at a height of 93.4 feet and has a storage capacity of 169,646 acre-feet, making it crucial for agricultural irrigation in the region. The dam, with a spillway width of 257 feet, also serves as a high-hazard potential structure due to its significant hydraulic height of 73 feet.

Over the years, Island Park has undergone multiple modifications to enhance its structural integrity and seismic resilience. The dam has been inspected regularly by the Bureau of Reclamation, with the last inspection conducted in July 2020. Despite its high hazard potential, the dam is rated to have a moderate risk level (3), indicating the need for ongoing risk management measures to ensure the safety of surrounding communities in Saint Anthony, Idaho. With its strategic location and critical role in water resource management, Island Park remains a vital infrastructure for sustaining agricultural activities and safeguarding against potential flood risks in the region.