An evaluation to establish baseline data on forest insect and disease activity near a magnesium plant under construction in northeastern Washington was initiated in 1974. The plant will emit significant amounts of sulfur dioxide. Data indicates that several fungal and insect species are at low populations. Needle retention appears normal on ponderosa pine and Douglas-fir. Some tip necrosis was found on pines and histological analysis of needles revealed a pollutant syndrome. Tissue analyses indicated total sulfur in pine and fir needles is about twice that found in "clean" areas in Montana. Sulfur dioxide may be drifting in from Spokane, Washington, or Trail, B.C., Canada. In spite of evidence of a small amount of sulfur pollution at present, the forested area in general appears in good health. The data will be a good baseline to which future evaluations can be compared after the magnesium plant begins production.