Fire-history records have important implications for understanding the controls of modern and future fire regimes in arctic and boreal Alaska. Charcoal in lake sediments provides a means to reconstruct past fires across different climatic and vegetational periods in this region, but interpreting charcoal stratigraphy is challenging because little information exists linking charcoal production to charcoal accumulation in sediment cores. I present a numerical model that simulates the major processes in this pathway and illustrate its use as a tool to evaluate the assumptions of charcoal dispersal and taphonomy and the merits of different approaches for analyzing charcoal records. This model 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. I also use lake sediment records to reconstruct fire return intervals (FRIs; the inverse of fire frequency) across a 150 km-wide study area in the southcentral Brooks Range of Alaska over the past 15,000 years. 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.