The War Bonnet Round Up is Idaho’s Oldest Rodeo. Held every year the first weekend in August, Idaho’s Oldest Rodeo is a PRCA sanctioned event and we aim to bring best rodeo contract personnel, talent, and stock to compete in our family-friendly atmosphere. Plan on our 111th Anniversary on August 3, to August 5, 2023, with a family kickoff event on Wednesday, August 2, at the Bank of Idaho Arena at Sandy Downs.