My father had a stroke and is now having more health and memory issues.He is married, not to my mom.Can I get guardianship?

Youcan file a petition for guardianship in probate court (it may have another name in OR). This is a very difficult thing to do when someone is married. You would have to demonstrate that the spouse is not a suitable guardian. You need an elderlaw attorney familiar with guardianship procedure. To be honest,most attorneys would not take this because as you posted the problem it is so long and expenseive to do. Also if you want his money and he has a will leaving it to her, there will be a brutal will contest.
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Mr. Sarno is licensed to practice law in NJ and NY. His response here is not legal advice and does not create an attorney/ client relationship. The response is in the form of legal education and is intended to provide general information about the matter in question. Many times the questioner may leave out details which would make the reply unsuitable. Mr. Sarno strongly advises the questioner to confer with an attorney in their own state to acquire more information.