Karl Weick's classic study of "sensemaking" showed that there is much to be learned from a wildland fire. In this tradition, we present an ethnographic tale from the subarctic to introduce the concept of ecological sensemaking"the process used to make sense of material landscapes and ecological processes. We then reanalyze data from the Mann Gulch fire and conclude that ecological sensemaking and ecological materiality were underappreciated dimensions of this historic tragedy. Comparisons of incidents and actors suggest that ecological embeddedness enables sensemaking and that inability to make sense of subtle ecological cues introduces hidden vulnerability.