Despite decadal declines in atmospheric mercury emissions and deposition, clear linkages with similarly trending biotic concentrations in the environment remain elusive. We evaluated interannual temporal patterns in biosentinel dragonfly larvae mercury concentrations from more than 100 sites in protected lands (e.g. national parks, national wildlife refuges, and national forests) across the US, and also assessed the relationships between watershed level atmospheric deposition and dragonfly larvae mercury concentrations from more than 700 paired site-year measurements across the US. Preliminary findings suggested high variability in site-specific temporal trends of dragonfly mercury concentrations, with some sites decreasing, some increasing, and some with no directional trends. Additionally, at the site-scale there were no relationships between paired wet Hg deposition or precipitation Hg concentrations and mercury concentrations in dragonfly larvae, suggesting a decoupling between delivery of atmospheric inorganic mercury to a waterbody and the amount of mercury accumulating through the food web. A substantial proportion of this variability can be explained by site-specific biogeochemical characteristics that regulate mercury bioavailability and methylmercury production. However, when accounting for variability associated with individual sampling locations, we found that at a national scale, annual average dragonfly mercury concentrations declined by approximately 16% between 2011 and 2020, and were highly correlated with average annual Hg concentrations in precipitation, which similarly declined by 19% over the same time frame. Collectively, our preliminary findings indicate that despite considerable site-level variation in relationships between Hg deposition and bioaccumulation, when integrated at a national scale, temporal patterns in mercury bioaccumulation are consistent with patterns in the amount of mercury delivered in precipitation.