Your question is a false one because all believers in Portland comprise the church of Portland even where only 2 or 3 are gathered. Next time someone asks you what church you belong to just say as they said in the Bible the church of Portland in the churches of Oregon.

The question you should be asking is who are the Elder(s) for the church of Portland in the churches of Oregon? They would have been appointed by the Apostle(s) working in the region of churches of Oregon. And the Elders would have approved of the Elders of the many meeting places in the church of Portland.