Editors' Summary: In working to protect species and enforce the Endangered Species Act, nongovernmental organizations (NGOs) generally take one of two possible routes: litigation or collaboration. While some NGOs primarily use confrontational efforts to force agency action, such as petitioning the government to list a species, filing lawsuits to require timely agency action, and challenging decisions not to list through litigation, other NGOs use cooperative efforts with private landowners and agencies to help protect and recover species. The author argues that NGOs should continue to specialize in one approach or the other and urges NGOs to coordinate their efforts to maximize results. Developing a cooperative strategy that uses both approaches will increase the efficacy of environmental efforts and lead to better results.