Open carry is legal in Oregon - except in a few select cities (notably Portland,) so you would be fine open carrying. Concealed carry requires an Oregon permit - which is "shall issue" for Oregon residents, and is "may issue" for residents of Washington, Idaho, Nevada, and California (bordering states) only. Oregon does not have reciprocity, you must have an OREGON permit for concealed carry.
Carry is legal in state forests and state parks. Federal lands are obviously contingent on Federal rules - which means yes except for buildings/etc.
Of course, as with any advice, I am not a lawyer, nor do I even play one on TV. Look up the laws for yourself. most gun laws fall in Link Removed, and the Oregon Firearm Federation has a FAQ of Oregon gun laws.
