Dave,
I had wondered about when the change took place. I was away from the Park from 1977 to 2001 (way too long). In the 1970s the hotels were staffed primarily by American college students. This worked out well because the hotel season only ran from about June 15 to the day after Labor Day as I recall. I suspect that once the hotels extended their season, they could no longer operate primarily with American college students because those students had to get back to school right around Labor Day. As a result, the hotel company probably started hiring more local people and international employees at that time. I don't know the present ratio between American college students vs. locals and international employees.
Imagine my shock when I walked into Lake McDonald in 2001 and saw that the front desk was staffed by two bald-headed old men
in place of the college students who used to staff it. Of course now I am getting to be an old man myself (but I still have hair).
I noticed the same thing in Acadia here in Maine. The place used to about close down after Labor Day but now there is a strong shoulder season and year-round. My daughter worked as a waitress at the Jordan Pond House, the only restaurant in the Park, for three summers. There were a lot of foreign workers there and she made a lot of friends. Some of them were very helpful to her when she visited Poland a couple of years later.
Lyman