Identify City On A R.p.o. Postmark

I'm trying to identify this postmark on a postcard I have.
I'm certain "SEAT" is Seattle. But "BELL PORTT" is confusing. Based on Postcard content, it originated in or near Seattle Washington. The recipient address was Portland Oregon.
But I don't think the other city in the postmark is Portland Oregon as the "BELL" makes no sense. Also, There are two "T"s in PORTT. Additionally, I found (online) a R.P.O. postmark of "SEAT & PORT". If the two starting and ending cities of that railway were Seattle and Portland, that would be the postmark used.
I'm also assuming "NORTH" is an abbreviation of the railway. Not very helpful as many, many railways had "North" in their names.
Any help would be appreciated.

MPOS catalog number W-15-c
Bellingham, Port Townsend & Seattle, 182 miles, Puget Sound steamboat
Rarity "V", which is quite good for a 20th century postmark.
Please show up the entire postmark/message side, thanks.

Also, "North" is the direction of travel, not part of the name of the railway.

That month and day is my birthday. I expect gifts from everyone next month. lol I'm kidding.

You should acknowledge the basic mis-step made at the start, causing some of the confusion. There was no "PORTT", the spacing difference between the two Ts is obvious when one is carefully looking to tell what it is, and the second T has a period (.) after it. Placement of ampersand (&) reinforces this.

So, looking for a "PORT T. " would have likely allowed you to find Port Townsend. Lesson, practicing "attention to detail" is a lifelong learning skill (speaking to myself as well).