As ice patches melt around the world, archaeologists are finding remarkably preserved artifacts emerging from millennia of deep freeze. Last April, Craig Lee of the University of Colorado at Boulder announced the oldest discovery yet: the foreshaft of a 10,400-year-old wooden dart, recovered from melting ice near Yellowstone National Park. The slender birch object still shows the marks left by its maker’s stone tools. Artifacts made of organic materials like wood—much less likely than stone to survive the millennia—give us “another window to the past,” Lee notes.
Over the past decade, “ice-patch archaeologists” have scoured the earth’s northernmost latitudes. Lee looked farther south in the Rocky Mountains, hunting in shady valleys and along north-facing mountain slopes. His success was a matter of timing as much as strategy: Organic artifacts begin to decay the moment the ice melts back. When Lee found the wooden dart, it was “lying under the clear blue sky, exposed,” he says.