Born in Vladivostok, Russia as Kyra Geintze, she spent two years in a Japanese concentration camp at the end of the 2nd Sino-Japanese War. At the end of World War II she met Frank Downton, an officer from Minnesota and the two settled in California. There Downton did what she had learned as a child in Russia and began training thoroughbreds to be hunters or eventing horses. She also started riding dressage and their estate in Atherton, California became home to Atherton Dressage. She won the US Championship in dressage in 1966 and won the individual gold medal at the 1967 Pan American Games. At the 1968 Olympic Downton was almost 55-years-old and was the oldest women to compete for the US at the Olympics since 1904.