The point of Entry would be Bellingham WA but any copy of a birth certificate would not remain at a POE it would be placed in an immigration file. A FOIA request would have to made with the Immigration Dept and good luck with that. They can’t even handle the files they have now!
There is a general record somewhere that list poeple who entered through various ports....We found our ancestors who came in at Galveston when it was not a part of the US....Greenbacks...Illegally made their way up the Mississippi and the Ohio rivers till they got to the Falls at Louisville.