I vividly remember backpacking through Painted Desert [1] in Arizona, by far the quietest place I've ever been (and you can viscerally feel it's because of a lack of life), and repeatedly remembering the visitor center exhibits talking about how it all used to be a lush forest.

[1] Scroll down towards the end for some photos => https://kayce.basqu.es/blog/road-trip-2019/