1. Photomosaic base map of the Willamette River Basin, Oregon a tool for land- and water-resource planning / [cartographic material] Yale Public content 1976. 2013-08-30T14:30:55Z. 2013-09-04T19:53:05Z. Geological Survey (U.S.). U.S. Geological Survey. English. Public. Willamette River Watershed (Or.).