Hungry Horse Dam

Adapted from Wikipedia:  Hungry Horse Dam is an arch dam on the South Fork Flathead River. 

The dam is 564 feet in height and was the third largest dam, and second highest concrete dam, in the world at the time of its completion in 1953.   The dam's spillway is the highest morning glory structure in the world.

 The Hungry Horse Project was built for irrigation, flood control, navigation, stream flow regulation, hydroelectric generation, and other beneficial uses such as recreation.  However, no irrigation facilities were built and the project has no irrigation obligations. Hydroelectric power generation is the primary purpose of the dam today. Flood control is the dam's other main purpose. The dam, reservoir, and surrounding area are used for recreation.