Around 1085, the ground northeast of present-day Flagstaff split open along a fissure nearly six miles long. Lava shot as high as 850 feet into the air, ash and cinders covered the surrounding landscape, and by the time the eruption ended, a new volcano stood roughly 1,000 feet above the land: Sunset Crater. But people were living there when it happened. Ancestral Puebloan communities farmed throughout the area. Evidence suggests earthquakes gave residents enough warning to evacuate, and no direct deaths from the eruption have been found. Homes and fields, however, were buried beneath lava and cinders. Then archaeologists found something incredible. Pieces of hardened volcanic rock recovered near Sunset Crater contain impressions of corn cobs and stalks. Researchers believe people deliberately placed corn around an active volcanic vent, possibly as part of a ritual during the eruption. The eruption permanently changed life in northern Arizona. Thick ash destroyed farmland clos...