Staying In Portland Oregon and looking for winery visit suggestions.

[TheEngineer]

I will be going to Portland in September with a client who has asked that I spend some time with him in the wineries.

I would appreciate some recommendations as to where to drive to for a day trip and some winery suggestions. These guys are good wine people and are not label chasers, though they like good bottles....everytime I pull out my credit card, the wines seem to get more expensive.......

On a personal note, I have never had the opportunity to travel much in this area so I'm looking forward to it too.

many thanks in advance.