Residency status determination if attending graduate school in Oregon but planning to return to home state of Tennessee

[Pago]

I will be attending doctoral school in Oregon but intend to maintain my residency/domicile in Tennessee. What are the rules for this? I will attend school for 4 years and then return to my TN home. I want to keep my TN license, plates and home of record (I am also a retired service-member with Tennessee as my official home of record.)   How/where am I classified as a resident and how do I pay taxes?

[MaryK4]

Tennessee is your domicile- because you intend to return and are keeping many of the incidents of residency in Tennessee you are a Tennessee resident.  Note if you make any money in Oregon while in school you will have to file a nonresident Oregon tax return.