Doing a little looking around it may come down to the specific area you are in.
Open carry of firearms is legal, but for those who do not have a concealed handgun license, cities and counties may regulate the open carry of loaded firearms in public places. Localities that prohibit non-licensed open carry of loaded firearms in public places include: Astoria, Beaverton, Independence, Newport, Oregon City, Portland, Salem, Tigard, and Multnomah County.