<P> Oregon ( / ˈɔːrɪɡən / ( listen ) ) is a state in the Pacific Northwest region on the West coast of the United States . The Columbia River delineates much of Oregon 's northern boundary along Washington state , while the Snake River delineates much of its eastern boundary along Idaho . The parallel 42 ° north delineates the southern boundary with California and Nevada . Oregon is one of only three states of the contiguous United States to have a coastline on the Pacific Ocean . </P>
what is the name of the river that forms the northern border of oregon
Columbia River