I presumed you knew about native Americans, but that doesn't mean the geologist considered them. Anyway, it's still relevant since many populations in the Sono

I presumed you knew about native Americans, but that doesn't mean the geologist considered them. Anyway, it's still relevant since many populations in the Sonoran and Mojave had highly intensive traditional agriculture. I assume those are the areas that were being discussed? The lack of what we'd traditionally call intensive agriculture in places like central valley is mainly just a historical semantic distinction. They cultivated and intensively shaped their local environments to maximize food production, but they weren't herding or clearing fields so it doesn't count.