The effects of highway construction on stream sediment loads were studied in Applemans Run basin, Columbia County, Pa., from October 1971 to May 1974. During the investigations, about 5,200 tons of suspended-sediment were discharged from the basin. Of this amount, about 2,700 tons, or about half the total sediment discharge, as derived from the highway construction area. Annual suspended-sediment yields from 17.5 acres under construction ranged from 40,000 to 66,000 tons/sq mi in the 1972 and 1973 water years, respectively. In the 1972 and 1973 er years of active construction, 83 percent of the sediment transported from the construction site was eroded each year in storms from January to June. Seasonal trends in sediment discharge for 1972 show that 69 percent of that year 's suspended-load was transported in April, May, and June, whereas less than 1 percent was transported in July, August, and September. (Woodard-USGS)