A map of Oregon including its cities can be found on the Travel Oregon website, which is the "Official Guide to Oregon Travel and Tourism Information." The website has a clickable interactive map divided into seven regions, each featuring its many popular cities.
The seven regions on the map include Greater Portland, Willamette Valley, Oregon Coast, Mt. Hood/ The Gorge, Central Oregon, Eastern Oregon and Southern Oregon. Ergo, if one is looking to locate a city within the Williamette Valley region, it is as simple as clicking that portion of the map. This particular region features cities such as Salem, Eugene and Springfield.