Montesano is Grays Harbor's county seat on the Olympic Peninsula.
In 1860 the county seat of what was then called Chehalis County was moved to "the place of J.L. Scammons". Mrs. Lorinda Scammon was very religious and wished to have the place named Mount Zion. Another early settler, Samuel James, suggested "Montesano" as having a more pleasant sound and meaning about the same. The suggestion was approved and soon after a post office was secured with the name Montesano.
- Grays Harbor County Courthouse. 1911.