According to the Oregon instructions:
A Resident of Oregon is an individual that:
- considers Oregon as their permanent home
- financial, social and family life is centered in the state
- is the place you intend to return to when you go away
- Spent more than 200 days in Oregon during the tax year
A Nonresident of Oregon is an individual whose permanent home is outside of Oregon during the entire year. If you are an Oregon resident and you maintained a permanent home outside of Oregon for the entire year and spent less than 31 days in Oregon during 2017, you are considered a nonresident for tax purposes.
A Part-Year Resident is an individual that moved into or out of Oregon during the tax year.
If one spouse is a resident and the other is not, file a joint nonresident return.