After a few years on F-1 status (first, as a PhD student, then on my OPT and STEM OPT), I finally acquired an H1B status through my job a few days ago via change of status (without leaving the country). I would like to travel to a more exotic place than a regular US state and possibly less expensive than Hawaii. However, I know that if I leave the country, I will need to obtain a stamp/visa in the US consulate to come back. And I've heard that for Russian citizens (like myself) this process nowadays takes weeks and months and carries additional risks. Given my limited vacation time, I don't want to do leave the US now. I came up with an idea to go to one of US Territories, e.g. Puerto Rico, however I still don't know if I can do that without the need to obtain H1B visa/stamp in my passport. I've read that I may need my Russian passport to enter Puerto Rico, but have not yet found information about coming back to the mainland US relevant to my case. I even asked an attorney that works for our company this question and they said "Domestic travel" is fine (like if I did not know that) without really explicitly telling me if going to Puerto Rico or other US Territories is fully considered a domestic travel. So, my main question is:
Given my H1B status and Russian citizenship, will I need to obtain a stamp/visa when I return from a US Territory (one of: American Samoa, Guam, Northern Mariana Islands, Puerto Rico, U.S. Virgin Islands) to mainland USA? I do have an American driver's license.
I would really appreciate if you could reference a document or a legit website that supports your answer, but of course general immigration knowledge and life experience would be very helpful as well.
I found a couple of similar questions here: