Fishless headwater streams carry nutrients, detritus, and invertebrates to downstream fish-bearing habitats, but the extent to which this delivery is transmitted through food webs to fish is only understood for some study systems. The objectives of this study were to 1) determine whether the quantity of drifting invertebrates originating from fishless headwaters affects fish downstream, and 2) demonstrate whether prey transport from headwaters, and the use of these prey by fish, varies across timber harvest regimes and climatic conditions. We examined 16 streams in the Wenatchee River sub-basin, Washington, whose catchments differed in climate and land use. We measured the density and biomass of drifting invertebrates entering fish-bearing reaches from fishless headwaters, and fish abundance, biomass and growth in response to prey inputs from headwaters. We then manipulated invertebrate drift (blocked, supplemented, or control) from headwaters and measured downstream fish responses (movement, growth, abundance and biomass). There was no correlation between invertebrate drift density and fish biomass or growth in 2006. Results of drift manipulations showed higher fish growth in habitats receiving more headwater prey in 2006, but not in 2007. Clarifying whether there are important trophic linkages between fishless headwaters and fish downstream will provide insight into how management of headwater habitats affects broader riverine ecosystem productivity.