The area was served first from the Milwaukie post office. In 1904, Creighton post office was established, named for Susan Creighton, on whose donation land claim the office stood. Postal authorities did not name the office "Oak Grove" in order to avoid duplication. There had once been an Oak Grove post office in Josephine County. The first postmaster was noted Oregon botanist Thomas J. Howell.
The area was served first from the Milwaukie post office. In 1904, Creighton post office was established, named for Susan Creighton, on whose donation land claim the office stood. Postal authorities did .not name the office "Oak Grove" in order to avoid duplication. There had once been an Oak Grove post office in Josephine County. The first postmaster was noted Oregon botanist Thomas J. Howell