While Nabokov was a prolific writer, he is best known for novels like *Lolita* and *Pale Fire*. He did write poetry in both Russian and English, but there's no record of him writing a poem specifically titled "Lines Written in Oregon."
It's possible you are thinking of another author or poem, or perhaps there's a misremembered title. If you can provide more context or details about the poem you're looking for, I might be able to help you further.