Basin and climatological characteristics, quality-assurance data and results, and water-resources data for North Fork Bens Creek, in Somerset County, Pennsylvania are available from August 1983 through September 1988. The lowest temperature (-30. 0 C) was recorded during January 1985, and the highest temperature (36.7 C) was recorded during July 1988. Snowfall accumulates mostly during January and February and averages about 69 in annually. Solar radiation is most intense from late May to early June. Pan evaporation averages 0.17 in/day during the growing season and 0.02 in/day during the nongrowing season. Sulfur dioxide and sulfate contaminants in the air have declined since 1977; nitrogen dioxide and nitrates have remained constant. Average volume-weighted pH for precipitation in western Pennsylvania is about 4.0. Quality assurance analyses show that chemical data collected from August 1983 through February 1986 were satisfactory. Precision of data quality for March 1986 through September 1988 are marginal to satisfactory. Monthly base flow water-quality data are available from August 1983 through September 1988. Continuous precipitation data are available from October 1983 through September 1988. Precipitation was typically higher than normal for the 1984, 1985, and 1986 water years. Continuous streamflow data are available for water years 1985 and 1988. The maximum recorded discharge of 92 cu ft/sec was observed on March 31, 1985. (USGS)