Thanks for contacting ask extension with your question about soil testing. 
The Benton County Master Gardeners offer free pH testing at their help desk, located in the Sunset building (4077 SW Research Way, Corvallis, OR 97333). They do not test for nutrients. The turnaround is about 1 week.
If you want a complete soil test, you will need to go to an analytical laboratory that charges a fee.
OSU College of Agricultural Sciences performs testing for a charge: Here is a link to their rates: Turnaround times may be several weeks:
https://cropandsoil.oregonstate.edu/shl/testing-services/soil-testing
There are several commercial laboratories that support Oregon and have about a one to two week turnaround. For most of them, you can mail in your sample and they will e-mail you the results. The following link is to an OSU publication "Analytics Laboratories Serving Oregon". The list of laboratories begin on page 3.
https://www.oregon.gov/ODA/programs/Pesticides/Documents/2020/AnalyticalLabsServingOregon.pdf
   Below are some tips for collecting soil for testing:

• Collect your soil sample from the area of the soil where the plant roots will grow. About 6 to 8 inches deep is good for most garden plants.
• Remove any roots, grass or mulch from the sample for the most accurate test result.
• On a budget? Collect soil from different areas of the garden and mix together into one soil sample. This will give you an overall idea of your garden soils.
• Trying to problem solve or fine-tune? Collect soil from individual garden areas and test each area separately. Make sure to name your samples and make a map so you can match the results with your garden!

Hope this helps!