In a paper recently published in听, Erich and John correlated landscape controls on sediment supply through direct measurements of water and sediment fluxes in over 80 drainage basins ranging in area from 1.4 to 35,000芒鈧�発m2 in the northern Rocky Mountains. These data show that the sediment supply is dominated by basin lithology, while exhibiting little correlation to factors such as relief, mean basin slope, and drainage density. Sediment concentrations increase as much as 100-fold as basin lithology becomes dominated by softer sedimentary and volcanic rocks, relative to basins with more resistant lithologies. At very high sediment concentrations, bed surface, subsurface, and bed load grain sizes converge and a transition from single-thread to to braided channel patterns is commonly observed.