“…The extensive literature on social science related to wildfire issues (McCaffrey, 2015) has studied risk perception, mitigation decisions and perceived consequences (Champ & Brenkert-Smith, 2016;Champ, Donovan, & Barth, 2013;Dickinson, Brenkert-Smith, Champ, & Flores, 2015;Gordon, Luloff, & Stedman, 2012); community pre-fire mitigation (Cohn, Williams, & Carroll, 2008) and adaptive capacity ; residents' actions and adaptation (Brenkert- Smith, 2006); and community social diversity and vulnerability (Paveglio, Nielsen-Pincus, Abrams, & Moseley, 2017;Paveglio, Prato, Edgeley, & Nalle, 2016). However, work to assess wildfire risk by integrating social and natural systems is relatively new (Cutter, Boruff, & Shirley, 2003;Davies et al, 2018;Gaither, Goodrick, Murphy, & Poudyal, 2015;Gaither et al, 2011;Oliveira, Zêzere, Queirós, & Pereira, 2017;Parisien et al, 2016;Wigtil et al, 2016) or applied at limited geographic scales (Fischer, Kline, Ager, Charnley, & Olsen, 2014;Nielsen-Pincus et al, In review;Olsen, Kline, Ager, Olsen, & Short, 2017;Paveglio, Edgeley, & Stasiewicz, 2018;Paveglio et al, 2016), leaving a gap in our knowledge about large-scale transboundary risk in relation to behavioral response to fire. Our first goal is to understand where transboundary large fire events originate and how they spread through a mosaic of land tenures, management jurisdictions and fuel models, and quantify their impacts on the communities of three socially and biophysically distinct fire-prone regions of the western US.…”