Baseline environmental characterizations of the lagoons and estuaries in the northeastern Chukchi and western Beaufort Seas, were conducted using a sediment quality approach based on water quality, sediment chemistry, and benthic invertebrate community structure. Resident fish body burdens were also assessed. The study area was subdivided into six estuaries/lagoons. Sampling sites were randomized within each embayment. Field operations were conducted off a smaller vessel launched from the RV Ron Brown. Concentrations of 194 organic and elemental contaminants were analyzed in sediment, plus stable isotopes of carbon and nitrogen. Habitat parameters (depth, salinity, temperature, dissolved oxygen, sediment grain size, organic carbon content) that influence species and contaminant distribution were also measured at each sampling site. A detailed benthic community condition assessment was performed at each site. Additional sites were established in the offshore zone near Wainwright in the path of previously proposed oil infrastructure development. The estuaries are relatively shallow embayments, with little relief along the shorelines. Sediment characteristics varied widely depending on location, but were either sand or silt. The water columns were turbid, high salinity, and were not stratified. The estuaries on the Beaufort side were colder than those on the Chukchi Sea.