It is not well documented, but it exists. A visit to an Oregon DMV office may be helpful.
http://www.oregon.gov/ODOT/DMV/pages/faqs/sb1080.aspxhttp://library.state.or.us/repository/2009/200904201057461/index.pdfhttp://www.opb.org/news/article/providing-dmv-proof-youre-who-you-say-you-are/Continuous Traveler
An applicant who travels continuously may use a residence address of "continuous traveler" if the applicant is a resident of or domiciled in Oregon but has no physical home in Oregon. For instance, an applicant who has retired from an Oregon employer may present papers indicating he/she sold a home in Oregon and purchased a motor home.