Ambient sulfates, total suspended particulates (TSP), and ozone data were collected in rural areas of New York and New Jersey as part of a study conducted jointly by the New York State Department of Environmental Conservation and the Interstate Sanitation Commission during July and August 1975. Relationships between these contaminants and various meteorological systems were examined. The sulfate and TSP data were obtained from 24‐hour integrated high volume samples obtained on a daily basis at seven rural sites with the emphasis in this paper being on two sites: Whiteface Mountain, N.Y., and High Point, N.J. The sulfate concentrations were found to be highest during four distinct periods which were generally defined by anticyclonic stagnation and/or return flow of maritime tropical air. The highest values recorded at Whiteface Mountain and High Point were 24 μg/m3and 20 μg/m3, respectively, in the period from July 21 through 25. During the other three periods, a maximum of at least 15 μg/m3was observed at one or both sites. Coincidence of the high level periods at the two sites separated by approximately 200 miles and at five other rural New York State sites during most of the study is a strong indication of long‐range transport. ‐The maximum sulfate concentration recorded during the study was 38 μg/m3at Schoharie, N.Y.