Hi, If you are still wondering about Millville we might be able to shed some light on that.We bought an old farmhouse 10 years ago out Aladdin Rd.In the walls we found some old postcards dated 1916 from Millville, Wa.We couldn't figure it out either except that Mill Creek runs by Aladdin Rd. Maybe the name came from that?We asked the Stevens Co. Historical Society about it and they told us that there used to be an old post office out Aladdin somewhere and this area was known as Millville.Don't know when the change was made to no longer use the Millville P.O., but all mail was then delivered to Colville. They didn't know exactly where the Millville Post Office was but it is suspected to be around 5 miles from Colville out Aladdin Road. Hope that helps.