In many western states, forest health is an immediate and growing concern. The pattern of historic use and management has altered the natural conditions of their ecosystems, making the forests much more susceptible to drought stresses, insects, and deseases. Scientists, resource managers, and policymakers are asking how healthy conditions can be restored, how further forest decline can be prevented, and how losses can be reduced. The general ecosystem approach is described, along with how science can be translated into action in a Sustaining Ecological Systems (SES) approach. The Blue Mountains in Oregon are highlighted as the specific example. An strategy for action on overall forest health is described.