John and his brother Mike started riding bulls and broncs in high school. They competed at the amateur level and then turned pro. In 1975 they started acquiring a few bucking horses and some bulls, eventually they gathered enough stock to produce some high school, college, and amateur rodeos. That same year, Don Kish was a junior in high school and was winning more than his share of rough stock events. He teamed up with John and Mike to form Growney Brothers Rodeo Company.
Each year since 1981, Growney Brothers Rodeo Company has provided stock to the National Finals Rodeo. They are credited with providing more horses and bulls to the NFR than any other rodeo company in the west. On ten occasions John has been nominated “Stock Contractor of the Year” and in 2000 he was awarded that title.