when my son and daughter-in-law take family trips, they include a look at college campuses when possible so that he and his sister can start thinking about it.

They aren't really "campus trips" in the usual sense.

Of course my mom was a guidance counselor. I had counted visiting well over a hundred schools at one point

who has been a college counselor for a long time, that is advising kids and parents on a path that leads to increased chance of acceptance to the university they desire.

While I don't believe he made recommendations on the start of actual visitations, the start of the the actual process of working on that goal starts even earlier than freshman year of HS. The process he recommends might be one that you shake your head at but it he has a track record.

you better be aiming for that goal before HS. I just thought the actual narrowing down of schools you may apply to, and thus visit, would occur later in High School.