Thank you for all the comments!
I now know which states I will be traveling through (it's more or less the great plains region) and I will pass:
Calgary, Billings, Denver, Austin, Oklahoma City, Kansas City to name the biggest ones.
On second thought I'm only looking for a fine lab to develop the 120 films and I will do the scanning at home in Europe.
However I don't feel comfortable with sending films to a lab because I don't trust the postal service (where I'm from it can't be trusted anyway)
and it wouldn't be practical since I will be on the road and in a different place nearly everyday.
So if anyone has recommendations for a professional excellent photo lab (I already went to labs where my negatives got stuck in their machine or where my negatives had weird marks on them and I don't want any of this) in one of the above mentioned city it would be of a great help.
Thank you in advance and stay safe!
C