Island Park Dam
Island Park Dam is operated by the U.S. Bureau of Reclamation in Fremont County, Idaho, United States. The dam lies in Targhee National Forest near Island Park. The zoned earthfill dam was built between 1937 and 1939 as part of the Minidoka Project, which provides water to irrigate farmland in Idaho's Snake River Plain.
The dam provides only water storage, impounding, which is distributed by the Cross Cut Canal to farms in Fremont and Madison counties in Idaho, and Teton County in Wyoming. The Island Park and Grassy Lake reservoirs were built as an alternative to construction of a larger project that would have flooded the Fall River area of Yellowstone National Park.