Intermittent Spring, also called Periodic Spring, is located in Swift Creek canyon in Star Valley, near Afton, Wyoming. It is the largest rhythmic spring in the world. The great great grandfather of the Olympic gold medalist Rulon Gardner is credited with the discovery. Gardner says, "He was up there logging. He went up and found a nice little place to get some fresh water. It was intermittent. It went, and stopped. So it was pretty amazing".