 The Pruitt Draw flow of the Teepee Butte Member released about with layers of basalt up to thick.The Wanapum Basalt is made up of the Eckler Mountain Member (15.6 million years ago), the Frenchman Springs Member (15.5 million years ago), the Roza Member (14.9 million years ago) and the Priest Rapids Member (14.5 million years ago).They originated from vents between Pendleton, Oregon and Hanford, Washington.