https://www.amazon.com/Mountains-Without-Handrails-Reflectio...
It's been 20 years since I read it, but iirc he is musing about whether things like paving the trails around Niagara falls to make them handicap accessible diminishes our ability to be awed by the natural experience.
I may well be mischaracterizing it, so if you want to read it yourself the whole thing appears to be online here:
https://www.nps.gov/parkhistory/online_books/sax/contents.ht...