This paper summarizes a presentation from the Congress Symposium, “The Introduction of the Emerald Ash Borer in North America, A Case Study of Invasive Species Epidemiology and Conservation of the Host Species.” It briefly discusses the state of Fraxinus (ash) taxonomy, ash as a landscape and forest tree, some of its specialized uses, including those by Native Americans, and its role in supporting other organisms. The devastation caused to native, North American ash populations by the introduction of Agrilus planipennis (emerald ash borer; EAB) to the Detroit, Michigan area has already led to the loss of tens of millions of trees. Diverse efforts are underway to document and slow EAB’s spread and develop appropriate biological controls. Scientific research on ash-EAB interactions, including the study of potential tolerance or resistance mechanisms, breeding and genetic-diversity analyses, and ash systematics, would all benefit from access to well-documented, diverse ash germplasm. To help redress this unfolding biological tragedy, a collaborative, international effort to conserve these important genetic resources has been organized. Fortunately, ash is amenable to ex situ conservation through seed storage and cryogenic storage of dormant winter buds. Key partners in this effort are described herein, with a focus on the coordinating organization, the USDA-Agricultural Research Service’s National Plant Germplasm System, along with a summary of progress to date and future plans.