It was a year when fire seemed to engulf the continent. Flames surged through the pinyon-juniper woodlands of the Southwest, the ponderosa pine stands of the Rocky Mountains, the mixed conifer forests of the Great Lakes region. The smell of smoke was everywhere. To this day, 1748 remains the biggest wildfire year in North American history, according to a sweeping new study of data recorded in the rings of trees. Hundreds of sites representing an estimated 29 percent of the continent’s forests show evidence of burning. The blazes that year were more extensive than even the worst fire seasons of the past decade, when the hot, dry conditions created by climate change have helped turn whole landscapes into tinder. Yet unlike modern wildfires — which increasingly burn hot enough to damage ecosystems and destroy human communities — the blazes that swept the continent in the middle of the 18th century did minimal harm to the landscape, researchers say. [A free subscription is required to read this article]