A barge on the Columbia River broke free from its moorings downriver of the Dalles Dam.   The 80 to 100 foot barge floated down the river for 5 miles before going aground.   The local Sherriff’s office reported the runaway barge to the Coast Guard.   The Coast Guard dispatched personnel to the scene.   An inspection of the barge showed that it had no hazardous materials and was no threat to navigation.    Later the same day the Sherriff’s office reported the barge had refloated and floated further down the Columbia until grounding again near Lyle, Washington.   Contractors arrived later with a tug to secure the barge.