The National Park Service (NPS) and U.S. Forest Service (USFS) manage areas in the Pacific Northwest (i.e., the states of Idaho, Oregon, and Washington), that contain significant natural resources and provide many recreational opportunities.  The agencies are mandated to protect the air quality and air pollution-sensitive resources on these federal lands.  Until recently, very few nitrogen critical loads studies had been conducted in the Pacific Northwest.  Because there are several sources of nitrogen in the region, NPS and USFS air quality staff became concerned that lack of nitrogen effects information would inhibit their ability to adequately protect Pacific Northwest park and forest resources.  Therefore, the agencies - with scientific input from the U.S. Geological Survey - developed a coordinated approach for accumulating additional nitrogen effects information and using the data in planning and regulatory arenas.  As a first step in that process, the agencies recently published a report that summarizes the current state of knowledge about nitrogen deposition, effects, and critical loads in the region.  The report's intended audience is NPS and USFS managers in the Pacific Northwest, state and federal regulatory agencies, and research organizations.  The report describes:  sources and effects of nitrogen deposition, legal mandates for NPS and USFS air quality protection efforts, the concept and use of critical loads and target loads to protect resources, and potential interactions of nitrogen and climate change.  The report also summarizes current nitrogen effects studies in the region and prioritizes data needed to improve understanding of how nitrogen affects regional ecological resources.