We propose to (i) reconstruct a record a record of past fires and their magnitude by detecting the occurrence of pyrogenic black carbon (BC) and the molecular fingerprint of past fires in sediments by measuring polycyclic aromatic hydrocarbons (PAHs), levoglucosan and lower chlorinated dibenzofurans (PCDFs). BC is a particularly resistant form of charcoal, indicative of high burn temperatures and fire intensity. We hypothesize that (i) the occurrence of natural fires can be detected by isolating BC in sediments; and (ii) selected PAHs, levoglucosan and PCDFs are robust molecular tracers of natural fires. We propose to test these hypotheses with sediment samples taken in Oriole Lake (Sequoia and Kings Canyon National Park), where an independent record of historic fire occurrence and fire extent is preserved in the scars of conifer trees. Secondly, we propose to correlate the occurrence and intensity of past natural fires with other indices of climate/drought (Palmer Drought Severity Index, PDSI) and vegetation change, such as stable C/N isotopes. In general, PDSI is constructed based on the records retrieved from tree-rings, which date back to ca. 1500 AD. Hence, we propose to use the sedimentary record to (i) verify the link between black carbon, natural fires and PDSI, and to (ii) extend the presence of severe droughts back in time. Stable isotopes of carbon and nitrogen are indicative of the composition of plants, and record changes in previous land cover and climate. This will enable us to reconstruct the conditions (vegetation, climate) that influenced fires prior to 1500 A.D., when tree-ring records are no longer available. We suggest that the sedimentary record enables us to detect changes in vegetation burnt, and how this relates to the occurrence of natural fires. Taken together, we can provide additional, vital information on past fires, namely what kind of vegetation was present before and during the burns. Is there a link between the kind of vegetation burnt and the magnitude of the combustion, as indicated by the organic tracer molecules and black carbon particles? Lastly, based on our detection of past natural fires, we can identify potential drought periods prior to 1500 A.D. for the Western U.S. We expect to write one manuscript out of the proposed research: The influence of vegetation and PDSI on natural fire events and their magnitude: A case study in Oriole Lake (CA). We anticipate that the results from our research will enable a much more detailed reconstruction of past fire occurrences and magnitude, which will be invaluable in better understanding past natural fires, and predicting future ones.