From 1928-1950, Hg was used as a catalyst during the industrial production of acetate flakes in Waynesboro, VA. Evidence surfaced in the mid-1970's that the environment in and around the South River (SR), a part of the Shenandoah River system, was contaminated with Hg some two to thirty miles downstream from the manufacturing site - the contamination apparently originating from undocumented spills during the catalyst recycling process. Since 2000, a consortium of scientists from different local, state, and federal agencies, private corporations, and public interest groups called the South River Science Team have been working to understand the extent of Hg infiltration into the environment, as a means for developing strategies for the eventual cleanup of the SR. The ongoing work presented in this paper is in support of this effort, investigating for the first time at the SR site, linkages between chemical character of adsorbed Hg and bioavailability of Hg for biotic methylation. Soil cores were taken on a transect crossing natural drainage channels on what is termed the Schifflet floodplain, a pasture farmland three-quarters surrounded by the SR. Hg chemical speciation will be characterized in terms of exchangeable vs. fixed Hg as well as associated soil cations by chemical extraction. Hg species will be characterized by XANES spectroscopy, and its association with other soil metals using micro-XRF mapping. Hg association with soil carbon will be presented using the combination of density separations and SEM/EDX analysis. It is our hope to these fundamental characterizations of adsorbed Hg will give sufficient information to postulate a reasonable remediation strategy for the contaminated soils at the SR site.