The evolution of the Libraries’ outreach at the Smithsonian’s National Zoological Park (NZP) and Conservation Biology Institute (SCBI) reflects how profoundly American zoos have changed in the last 50 years. What used to be called wildlife management is now conservation biology, and the traditional study of animals based on physical characteristics has evolved into an investigation based on genetic distinctiveness. As the care and study of wild animals become increasingly sophisticated, the Libraries’ expanding collections and evolving services are more critically needed than ever before.