Where did Beacon Rock come from? Did it come from Mt Hood when Mt Hood blew its top?

.... Indian folklore says Mount Hood through it at Mount Adams they're fighting over Mount Saint Helens whom they both loved. I've Been Told that it's a volcanic plug the landed there and also that the Montana flood formed it only God knows

They have plaques all over explaining it. If I remember correctly, it was shaped during the Missoula floods.