Main channel of Tanana River above Wenrich Island Gallery Date Observed: Dec 16, 2006 Video: Click image to play Sam Demientieff talks about open water here in the main channel of the Tanana River above Wenrich Island and the fact that it is on one of the three channels of the Tanana River. He has never seen open water here in the past. Processes Observed Changes in River Channel, Open Water Thin ice and open water toward the center of the main channel of the Tanana River above Wenrich Island. Processes Observed Open Water, Thin Ice