Ryan Ann Hunter is a pen name for Pamela D. Greenwood and Elizabeth G. Macalaster, who have teamed up to write books about bridges, tunnels, skyscrapers, airplanes, robots, the history of flight, and women spies. Their books have garnered several awards, including the Children's Book Sense Pick, the Chicago Public Library Best of the Best, Parenting magazine Book of the Year award, Oppenheim Toy Portfolio Gold Best Book award, and Austin Young Engineer's Award.