An exhibit by Hood River photographer Peter Marbach showing the Columbia River from its source in the Rocky Mountains of British Columbia to the sea will open Wednesday at the Oregon Historical Society in Portland. The exhibit features 25 of Marbach’s photographs showing both the river and the people along it. Marbach is hoping to spark awareness of the on-going Columbia River Treaty discussions between the United States and Canada, and the opportunity that brings to restore fish runs to the upper reaches of the river in Canada. The exhibit will be at the Oregon Historical Society in downtown Portland through April 1, and Marbach hopes to take it to other locations after that. The exhibit had been scheduled to open this weekend, but was delayed by snow and ice this week in the Portland area.