Data and code for: Wildfire activity in northern Rocky Mountain subalpine forests still within millennial-scale range of variability

Increasing area burned across western North America raises questions about the precedence and magnitude of changes in fire activity, relative to the historical range of variability (HRV) that ecosystems experienced over recent centuries and millennia. Paleoecological records of past fire occurrence provide context for contemporary changes in ecosystems characterized by infrequent, high-severity fire regimes. Here we present a network of 12 fire-history records derived from macroscopic charcoal preserved in sediments of small subalpine lakes within a c. 10,000 km2 landscape in the U.S. northern Rocky Mountains (Northern Rockies). We used this network to characterize landscape-scale burning over the past 2500 yr and evaluate the precedence of widespread regional burning experienced in the early 20th and 21st centuries. We further compare the Northern Rockies fire history to a previously published network of fire-history records in the Southern Rockies. In Northern Rockies subalpine forest..., We provide paleoecological fire-history data used to support the analyses and results in Clark-Wolf et al. (2023). These data are from 12 lake-sediment records from within a c. 11,000-ha landscape in the northern Rocky Mountains, USA, spanning 46.6 to 47.5° N and 114.6 to 116° W. Sediment cores were collected from the deepest part of each lake in 2017 to 2019. Sediment cores were dated based on 210Pb activity in the upper sediments, as well as tephra layers from known volcanic eruptions and 14C dating of terrestrial macrofossils or concentrated charcoal. Sediment cores were sliced at 0.5-cm intervals and subsampled contiguously for macroscopic charcoal analysis. Charcoal pieces were counted under a stereomicroscope and used to calculate charcoal accumulation rate, which was analyzed using peak detection methods to identify peaks in charcoal accumulation inferred as local fire events. To produce a composite record of fire history across the study area, the percent of sites recording loca..., Data are provided as .csv files, and code is provided as a .R script file to be opened in RStudio (open source).Â