The Athabasca oil sands region (AOSR) is one of the largest unconventional oil reserves globally, and is projected to become increasingly important as conventional oil resources are depleted. This has lead to increasing concerns about the impact of industrial emissions on surrounding ecosystems. Four sediment cores from three lakes in northeastern Alberta and northwestern Saskatchewan were analyzed to assess the type and quantity of organic matter (OM) in sediments, and whether there had been any impact from industrial emissions originating in the AOSR on lake sediment geochemistry. Analyses showed that sediments in all three lakes are organic-rich, and the OM is dominantly derived from authochthonous primary production of phytoplankton and bacteria. Stable N and S isotope analyses of sediments, deposited between 1850 and 2010 showed no clear impact from industrial emissions in the AOSR.