I would suggest that you go to www.switchboard.com
and you will find 42 listings for Birklid in the USA. You can narrow it down to North Dakota if you'd like, but I suggest you write a letter with your questions, photocopy it, and mail it to all of those found on Switchboard. I have had excellent luck doing that. There might be another Birklid genealogy buff out there you don't know of yet.
There are three in North Dakota, one living at Fort Ransom, which was also the name of the county where the naturalization records were filed?
There is a Birklid query board at Ancestry.com, but no one has posted there ever. You could be the first.http://boards.ancestry.com/mbexec/board/an/surnames.birklid