NEWPORT, WASHINTON—Idaho State Journal reports that evidence of earth ovens dating back some 6,000 years have been found on the banks of the Pend Oreille River in northeastern Washington state. Members of the Kalispel Tribe and archaeologist Shannon Tushingham of Washington State University found the fire-cracked rocks in clusters about four feet below ground surface while investigating the site ahead of a construction project. “This is some of the oldest technology used by humans to cook food anywhere in the world,” Tushingham said. “And here, we have some of the oldest ovens in North America.” Carbon dating of the site shows that people repeatedly returned to it between 6,000 and 700 years ago, she added. “That is a fairly continuous history of food processing on the same land that speaks to both ecological and cultural stability,” explained Kalispel tribal archaeologist Kevin Lyons. The bowl shape dug into the sandy soil would have been lined with fuel and capped with rocks. Tradition indicates that food was then wrapped in a non-burnable layer and set on the rocks. The fuel was lit and the oven covered with soil, leaving vent holes, so that the food could bake. The researchers will take samples from the ancient ovens to look for any traces of food residues. To read about 1,000-year-old balls of clay that were used to cook in the Yucatán, go to "Artifact."