We recently bought a home on Ashland, OR but we work in Seattle, maintain a home there and will continue to do so. We will spend 30 to 45 days on holiday a year at the new home. We can't figure out if we are going to have to pay income tax in Oregon and, if so, if it is prorated. What is the story?

You are definitely Washington state residents.

You will have to pay Oregon property taxes, but that should be all you pay.