So, I work in Alaska and I have a mailing address in Alaska, but I'm also renting an apratment in Oregon, and I travel back and forth every month. I earn nothing while in Oregon, and spend less than 6 months a year in Oregon. A friend advised me to file as a part time resident, and that way I could claim moving expenses for when I moved my stuff to this Oregon apartment, but wouldn't have to pay Oregon state tax. That friend is not a tax expert, but was in a similar situation some years back. Is this valid and how does one go about filing as a part time resident?

Just file the part-year resident form for BOTH states.

It seems to be a valid method of filing.