100% Traveling Consultant with no-home address

I am a consultant who travels to a new location somewhere in the world around every month.

My parents live in Oregon, so my drivers license is an Oregon's driver's license. However, I probably spend only 2-3 weeks out of a year in Oregon. 

Because of the low amount of time I stay in any particular location, I am very confused as to how I should file my state taxes. When I look at my pay documents, I am getting tax withholdings not only in Oregon but a bunch of other states I have worked in. I am hoping to get a refund for these multi-tax scenarios. Can someone help clarify how exactly my state taxes are supposed to work?