To assess historical PCB loading and spatial distribution in the Steinberger Slough and Redwood Creek (SS/RC) complex, a passive sampling campaign was conducted in the summer of 2020 at eight selected sites. Passive sampler uptakes (CPE) successfully captured PCB distribution patterns at each site, and depicted cross-site differences and site-specific characteristics at a fine resolution of 1-cm subsections within the sediment. As expected, based on previous work, the Pulgas Creek outlet and Seaport stations showed elevated PCB concentrations compared to other less-contaminated sites. The region outside of a detention pond area was monitored for the first time in this study, and revealed very high PCB signals along the sampled depth. Interestingly, CPE at the sediment surface inside the detention pond was the lowest among all monitored sites, which may indicate a significantly reduced PCB loading from the watershed draining area, and consequently a reduced loading from the detention pond to the complex relative to other sub-watersheds. Calculated freely dissolved PCBs (Cfree) also presented a similar story to that of passive sampler uptake data, but longer deployment is recommended for better assessment with performance reference compounds. Another objective of this study was to compare passive sampling measurements to conventional sediment concentrations. Total extractable sediment PCBs normalized by total organic carbon showed a better association with the bioavailable fraction determined by passive sampler uptakes than sediment PCB concentrations alone. Ex-situ PE uptake free of site hydrodynamic conditions showed the best correlation with normalized sediment PCBs. Despite influences from on-site conditions, in-situ passive sampler uptake correlated with ex-situ passive sampler uptake, and the correlation was better with each site considered separately. Although more data are needed to draw a generalized conclusion, passive sampling data will deliver contaminant bioavailability information corresponding to the combined information of sediment contaminant concentrations, total organic carbon concentrations, and porewater transport rates. Planned food web monitoring at these stations can provide valuable information for further evaluation of the benefits of passive sampling data in risk assessment.