Speaking as a lyricist raised in a family of historians, I feel the original poster's pain, and I deduce from the phrasing that it's a matter of the place name being woven deeply enough into the lyrics that any rewrite would necessarily end up amounting to an entirely different song (to use some examples from my part of the world, it would be like trying to switch Tillamook for Seaside, Pasco for Walla Walla, or Chewelah for Twisp).

That being said...one question for me would be how much accuracy of place matters to the story told by the song. If the song is a story about how a town was founded, or some quirk of geography is integral to the events narrated, then an error of location is probably very significant. If it's a story about a shipwreck or a mountaineering accident, then it may be less critical that it happened nearer to Astoria than to Bandon, or on Mt. McKinley rather than Mt. Rainier.

It may be enough in the specific case for a performer to note that sources differ as to the location of the events described, or to flat-out admit in one's introductory patter that the song was written based on incomplete historical data (but that the story is still true even if misplaced).