It is okay to OC in Oregon whether you are a resident or not. There are some restrictions however, and the flyer does a good job of pointing those out. Basically, no government buildings of any kind and you cannot have it loaded when in a "ban" city. I don't know if Roseburg is a ban city (the flyer has a list but look it up online yourself (city codes)).
To carry in a vehicle DO NOT lock it in a glove box (that is concealed). Simply keep it on your side, OC, in a belt holster or place it on the seat. Again, cities with bans require that it be unloaded due to a court case a couple years back.
Read the flyer and check the Oregon Revised Statutes just google "oregon revised statutes" and then look for chapter 166. Start reading at 166.170. It's not very long at all.