.....the reason to stop at PP is to check into the park and pay fees...Not to clear customs assuming you have a valid RABC permit.

The point of the RABC permit is to allow you to cross into Canada, at will, within a defined calander period and geographical area.  When you apply for, and obtain the permit...you essentialy "clear Canadian customs" for that permit period (1 year).

The permit is a Canadian document...not a US document.  Since you can cross "at will" into Canada on the permit....without clearing at an official Canadian port-of-entry, there is no "paper trail" as to when you've crossed into Canada.  The US still requires you to visit a port-of-entry on return to the US.

How does the US know if you've been in Canada "at will" on your Canadian RABC?   They don't.  It's a voluntary process if you are traveling under your own power.  If you check into a Canadian govmt run park and pay fees....in that sense you have left a "paper trail".  Is that data shared with or available to US Customs?  To the best of my knowledge it isn't.


Arrowhead...."does everyone stop in at US Customs upon return?"  Why yes, everyone does.