In the Middle Awash River Valley , cone-shaped depressions of reddish clay were found that could be made by temperatures of 200 Â C. These features are thought to be burned tree stumps such that they would have fire away from their habitation site . In the Middle Awash River Valley , cone-shaped depressions of reddish clay were found that could have been created by temperatures of 200 Â C. These features are thought to be burned tree stumps such that they would have fire away from their habitation site .