This data release includes three categories of data that were compiled as part of a study of sediment and solute transport and landscape denudation in watersheds of western Oregon and northwestern California: 1) mean annual loads of suspended sediment, total suspended solids, and silicate solutes at fixed water-quality stations; 2) fluvial transport of bedload, suspended sediment, and silicate solutes; and 3) mean concentrations of silicate solutes at fixed water-quality stations.