The concentrations and distributions of polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (oxy-PAHs) in stream sediments collected from thirty-four sites along the Conodoguinet Creek were measured and analyzed. The sites are well-characterized in terms of adjacent land-use features as determined using Geographic Information Systems (GIS) data. It was found that urban areas are characterized by elevated concentrations of PAHs and oxy-PAHs representative of pyrogenic processes. A combination of GIS data and principal component analysis (PCA) were employed to interpret the concentration data, and the results demonstrate that oxy-PAHs show a higher potential than PAHs to distinguish among different pollutant sources in an urbanizing watershed. This work is, to our knowledge, the first study to propose oxy-PAHs as unique chemical markers that can serve as proxies for various land-use practices, and may aid in identifying pollutant sources that contribute to ecosystem decline.