Executive Summary: The Forest Sustainability Assessment for the Northern United States provides a snapshot of today’s forests and a baseline for tracking future trends. This comprehensive assessment of forest sustainability is organized according to an international system of criteria and indicators known as the Montreal Process. Criteria define broad categories of sustainability; indicators are specific measurements within each category. The criteria address biological diversity, the productive capacity of the forest, ecosystem health, soil and water resources, global carbon cycles, socioeconomic benefits from forests, and the legal, institutional, and economic systems that can impede or enable progress in sustainability. This report covers the Northern United States—the 20-State region stretching from Maine to Minnesota, south to Missouri, and east to Maryland. The report was sponsored by the USDA Forest Service’s Northeastern Area, State and Private Forestry and the Northeastern Area Association of State Foresters. It provides foresters, policymakers, landowners, and the public with information on factors that could affect forest sustainability.