Left: modified satellite image of California as it may have looked in 1851, by Mark Clark. Right: satellite image of California now.
I hadn’t realised until I visited the Bay Model in Sausalito how much the water system of California was changed by Europeans, right from the start of its time as a US state. The huge amount of rock and silt washed down the mountains by the forty-niners started a rapid process that was only aided by the needs of agriculture and industry.
To paraphrase what Deb Chachra wrote about England recently, if it looks like it’s been terraformed, that’s because it has.