Mercury is a ubiquitous and toxic metal, whose negative impacts on human and wildlife health have generated considerable interest among researchers and policy makers alike. Research on mercury has largely focused on its transport and transformation in the atmosphere or transformation and accumulation in biota, particularly in aquatic environments. Notably, there has been relatively little attention devoted to mercury in soils, despite the fact that soil pools are an important sink for atmospheric mercury, as well as an important source for re-emission to the atmosphere and leaching into downstream aquatic ecosystems. This paucity of information on mercury in soils can be attributed to difficulty in acquiring uniformly collected datasets containing adequate spatial and temporal coverage with which mercury patterns can be examined. Here, we present an analysis of mercury from a large soil survey (3 horizons, ~4,800 sites) across the coterminous US, collected by the United States Geological Survey. Spatial patterns of mercury in soils are largely driven by organic carbon content and vary markedly over different ecoregions and land use types. Median mercury concentrations decrease downward through the soil profile and are greatest in forested and developed landscapes. Concentrations are highest in heavily forested ecoregions and those along the Pacific coast, while North American Deserts contain the lowest concentrations.  Mercury soil pools are calculated for the top 1 m of soil and are substantially larger than previous estimates focusing on only organic soils. Using mercury-to-titanium ratios as a proxy for native Hg fractions, we estimated that between ~73 – 97% of total mercury is derived from external additions. Finally, recent soils pools (2007 – 2010) compared to older surveys (1961 – 1974) find that mercury in soils has dramatically decreased (~ 56%) over ~ 60 years, suggesting that soil mercury may be more dynamic than once thought.