This study reconstructed the fire history and vegetation at a network of sites in the southcentral Brooks Range, Alaska, in order to understand how fire regimes have evolved over the past 15,000 years in relation to climate and vegetation. Lake sediment records were used to reconstruct fire return intervals (FRIs). Fossil pollen, stomata, and modern analog analyses document four major shifts in vegetation over this period. At millennial time scales, fire-regime changes showed greater correspondence to changes in vegetation than to changes in inferred climate. For example, FRIs increased with climatic warming associated with a shift to deciduous forest c. 10,500 years ago, and FRIs decreased with climatic cooling associated with the development of the modern boreal forest c. 5500 years ago. These patterns suggest that vegetation strongly mediated the direct impacts of millennial-scale climatic change by modifying landscape flammability. Within the boreal forest period (5500-0 years ago), fire histories reveal varying sensitivities of the fire regime to moisture and/or temperature changes. A subtle but statistically significant decrease in FRIs is associated with a shift from drier to moister conditions 2700 years ago; fire regimes were insensitive to a climatic shift c. 1200 years ago; and mean FRIs increased by 50% with the onset of Little Ice Age cooling 450 years ago. These varying responses emphasize the need for a rigorous understanding of climatic and non-climatic variables to anticipate fire regimes under future climatic scenarios. In addition to reconstructing vegetation and fire history, this study modeled the processes linking charcoal production and charcoal accumulation in lake sediments in order to gain a quantitative understanding of the assumptions and implications that go into interpreting sediment charcoal records for the purpose of fire history reconstructions. The modeling suggests that existing assumptions of charcoal dispersal distances are too simplistic but supports the use of current analytical techniques for decomposing charcoal series to infer local fire occurrence.