Toxic trace metal pollution introduced to watersheds through historic mining practices is a significant cause of freshwater impairment worldwide. Toxic trace metals are known to impact macroinvertebrate communities through a diversity of pathways resulting in altered community composition, reduced diversity, and sometimes lower abundance. The translation of these community impacts to secondary production has been much less studied. Macroinvertebrates are crucial contributors to the aquatic food web. Their secondary production determines food availability for aquatic and sometimes riparian predators, as well as potentially transferring contaminants to these consumers. In this study, we are documenting secondary production of the macroinvertebrate community at five sites within the Spokane River watershed with varying levels of toxic trace metals. The Spokane River watershed is directly impacted by historic mining practices that have deposited silver, lead, zinc, and other toxic metals throughout the watershed. A previous study showed that metal concentrations in macroinvertebrate tissue decease with distance downstream of mining facilities in the Spokane River Watershed. We anticipate that sites with higher toxic trace metal accumulation will have lower secondary production because of reduced macroinvertebrate diversity and lower growth or survival of specific populations. To test this hypothesis, we are estimating annual benthic macroinvertebrate secondary production for the 2025-2026 water year for each site using the cohort production interval method. We are also determining trace metal concentrations in water samples and invertebrate tissue through ICP-OES analysis. In our initial round of sampling (November 2025) and ICP-OES analysis, the Saint Joe River contained diverse mayflies and stoneflies and the lowest zinc concentrations at undetectable levels. The Spokane River sites were dominated by Diptera in the families Chironomidae and Simuliidae with intermediate levels of zinc at 0.023mg/L at the upstream site and 0.019 at the downstream site. The South Fork Coeur D’Alene River was dominated by Ephemeroptera, mostly in the family Ephemerellidae with the highest zinc concentrations at 0.608mg/L. As more macroinvertebrate and metal data is collected secondary production will be estimated for each site, determining if toxic trace metals could potentially have an impact on secondary production in the Spokane River watershed.