I would dig round in the
http://www.leg.state.or.us/ors/ myself before risking the consequences but here are some links for you.
http://opencarry.org/or.html
Summary
Oregon is a traditional open carry state. However, their preemption statute only covers concealed handgun license holders from city or county passed bans against loaded firearms in public places. To our knowledge, only the cities of Portland, Beaverton, Tigard, Oregon City, Salem, and Independence have passed loaded firearms bans encompassing all public places, and other cities have passed bans specific to Parks. Also, all "public buildings" are also off limits throughout the entire state unless you have a concealed handgun license.
http://egov.oregon.gov/OSP/ID/chl.shtml
Carrying Concealed Weapons in the State of Oregon Frequently Asked Questions
Q: I am planning a vacation in Oregon and would like to find out the validity of my concealed pistol permit, as well as any regulations for carrying my pistol.
A: Oregon does not recognize other states’ concealed weapons permit/license. Carrying a concealed weapon in Oregon is considered a Class A Misdemeanor as unlawful possession of a firearm. According to ORS 166.250 "(1) Except as otherwise provided in this section or ORS 166.260; 166.270, 166.274, 166.291, 166.292 or 166.410 to 166.470, a person commits the crime of unlawful possession of a firearm if the person knowingly:
1. Carries any firearm concealed upon the person
2. Possesses a handgun that is concealed and readily accessible to the person within any vehicle
We suggest that firearm(s) be placed in a storage container in the trunk of the vehicle or a locked storage area in a motor home. If pulled over, you may want to notify the police officer that a weapon is stored in a locked compartment of the vehicle.
http://www.nraila.org/GunLaws/#?st=OR
CARRY
It is unlawful to carry concealed upon the person or concealed
about one’s person in a vehicle any firearm unless one has a license to
carry a concealed weapon. Exceptions to the above prohibition are:
• persons possessing a handgun at their home or place of
business;
• organizations, which are by law, authorized to purchase or
receive weapons from the United States;
• policemen and law enforcement personnel, whether active
or honorably retired;
• military personnel when on active or reserve duty;
• members of a shooting club while at a range or going to and
from a range;
CAUTION: Firearm laws are subject to frequent change and court interpretation. This summary is not intended as legal advice or
restatement of law. This summary does not include federal or local laws, ordinances or regulations. For any particular situation, a
licensed local attorney must be consulted for an accurate interpretation. YOU MUST ABIDE WITH ALL LAWS: STATE, FEDERAL
AND LOCAL.
This may be reproduced. It may not be reproduced for commercial purposes.
• licensed hunters or fishermen, while engaged in hunting
or fishing or going to and from a hunting or fishing
expedition;
• merchants transporting or possessing firearms as
merchandise;
• duly authorized military or civil organizations while
parading or traveling to a meeting of their organization;
• corrections officer while transporting convict.