Island Park Dam is operated by the U.S.

Bureau of Reclamation The Bureau of Reclamation, and formerly the United States Reclamation Service, is a federal agency under the U.S. Department of the Interior, which oversees water resource management, specifically as it applies to the oversight and opera ...

in Fremont County,

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyomi ...

, United States. The dam lies in

Targhee National Forest Targhee may refer to: * Targhee National Forest, now the Caribou-Targhee National Forest a federally protected woodland in Idaho and Wyoming, United States * Targhee sheep, a domestic breed developed within and named for the forest * Grand Targhe ...

near Island Park. The zoned earthfill dam was built between 1937 and 1939 as part of the

Minidoka Project The Minidoka Project is a series of public works by the U.S. Bureau of Reclamation to control the flow of the Snake River in Wyoming and Idaho, supplying irrigation water to farmlands in Idaho. One of the oldest Bureau of Reclamation projects in t ...

, 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 Madison may refer to: People * Madison (name), a given name and a surname * James Madison (1751–1836), fourth president of the United States Place names * Madison, Wisconsin, the state capital of Wisconsin and the largest city known by this ...

counties in Idaho, and Teton County in

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...

. The Island Park and Grassy Lake reservoirs were built as an alternative to construction of a larger project that would have flooded the Falls River area of

Yellowstone National Park Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowst ...

Climate

Island Park Dam has a

humid continental climate A humid continental climate is a climatic region defined by Russo-German climatologist Wladimir Köppen in 1900, typified by four distinct seasons and large seasonal temperature differences, with warm to hot (and often humid) summers and freezing ...

(

Köppen Köppen is a German surname. Notable people with the surname include: * Bernd Köppen (born 1951), German pianist and composer * Carl Köppen (1833-1907), German military advisor in Meiji era Japan * Edlef Köppen (1893–1939), German author and ...

''Dfb'') bordering upon a subalpine climate (''Dfc''). Summers feature very warm afternoons and chilly mornings, whilst winters are freezing and very snowy with an annual snowfall averaging and reaching between July 1974 and June 1975. The dam’s weather recording site holds the record for the eighth-lowest temperature recorded in the United States (and lowest temperature recorded in Idaho) at .

References

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External links

Island Park Dam
at the Bureau of Reclamation Dams in Idaho Buildings and structures in Fremont County, Idaho Minidoka Project United States Bureau of Reclamation dams Dams completed in 1939 1939 establishments in Idaho