Though the two previous answers are correct, let me go a little bit deeper.
You will have to pay the Oregon state income tax if you either live or work there.
In Washington, there is no state income tax. There is a business tax though. As a Washington resident, you will have to pay sales tax (no sales tax for food). But as an Oregon resident, if you show your ID, you will be not charged with it.
But there are more financial advantages if you are living north of the Columbia River: The home prices in Clark County, WA are about 20% lower than in the Portland area and also the property taxes are substantially less than in Portland (15-30%).
So if you want to save a decent sum of money, buy in the Vancouver area (as we did for the same reasons). I think that Portland is more fun and there are more things to do, but all it takes is just a short drive over the bridge :).
I hope this rounds up the answers.
I hope all is well, I know your last planned visit met with some family hardship and I hope all is well with you and yours. To answer your question about tax, we decided to retire in WA to avoid the state income tax in Oregon. The sales tax in WA is not on food items and anything other that we simply drive 15 minutes over the bridge to Oregon and purchase there, best of both worlds living this close to the state line. Let me know when we can talk or you can reach me anytime so we can discuss any changes in your needs since we last communicated. I look forward to talking and picking up where we left off.
Troy Jensen, Buyers Broker
Professional Realty Services of WA
Oregon has an income tax so you would end up paying Oregon income tax if you work in Oregon. Washington state has sales tax on goods and no income tax.
Let me know if I can be of assistance to you and your wife.