Oregon Physical Features Map
This is a excellent map that shows the physical features of the state of Oregon.
Source: Oregon Blue Book

Oregon Physical Features Map
This black and white map shows the counties and the major freeways in the state of Oregon.
Source: Oregon Blue Book

Outline Map of Oregon
This is a basic black and white map showing the county lines as its only details.
Source: Indiana State University

Annual Average Precipitation Map
This map shows the average annual rainfall in the state.
Source: Spatial Climate Analysis Service, Oregon State University

Oregon State Map
If you need a map that shows the major freeways in Oregon, this is it!
Source: World Sites Atlas

Merriam Webster Atlas
This atlas page shows the Oregon state map and some quick facts. There's also a good explanation of the symbolism of the state flag.
Source: The New York Times and Merriam Webster