A long term study of turbidity trends in the Upper Deschutes watershed in Thurston County by Weyerhauser have indicated that improvements in forestry road construction practices have made a significant difference in reducing sediment in the Deschutes river and its tributaries.   Maryanne Reiter explained that the analysis of data from 1974 to 2004 suggested that even when adjusting for flow levels there is a clear correlation with reduced turbidity in the river and better road construction practices that have reduced sediment runoff.