Marine-derived nutrients (MDN), delivered to streams by spawning salmon, are an ecologically important flux that contributes to the productivity of stream and riparian ecosystems.  Documenting MDN movement through foodwebs and its variability among stream reaches will improve our understanding of MDN effects.  Our objective was to examine the ability of stable isotope and fatty acid measures of MDN assimilation in stream-resident fish to differentiate among sites that vary in spawning salmon abundance.  We sampled Dolly Varden spring through fall in regions that differed in nutrient concentrations and potential limitation due to underlying geology.  Dolly Varden δ¹⁵N and δ³⁴S correlated positively in streams draining granitic watersheds (r=0.89) and were consistently higher at sites with relatively high salmon abundance.  In sedimentary watersheds, however, δ¹⁵N and δ³⁴S showed narrow ranges and values were relatively high from both salmon and salmon-free sites, suggesting isotopically enriched watershed nutrient sources obscured the effect of MDN on isotope ratios.  Fatty acid signatures detected MDN when quantified as ω3:ω6 but not when quantified as multivariate distances from salmon flesh or eggs.  Given the responsiveness to MDN loading and the low analytical cost, we recommend stable isotopes for watershed-scale MDN tracking given the salmon-free end member is isotopically depleted.