From 1958 through 1960, a Sioux Falls-based Raven Industries development team led by Ed Yost, working under contract with the United States Navy, developed a self-powered hot air balloon capable of sustained flight. Its first flight on Oct. 22, 1960 marked the beginning of a new era of balloon flight. Over the following decades, hot air ballooning grew as a sport and spread worldwide, with Raven leading the way.