This isn't a huge surprise if you do much air travel (from which vantage it is, in fact, noticed). But it's still pretty cool.
Forty Years Ago, America’s Farms Completely Changed Their Shape—And No One Noticed
Do you think you know what a cornfield looks like? You don’t know what a cornfield looks like.
Interesting minor historical note: the center-pivot sprinkler was invented by a guy who lived in eastern colorado, out by Hudson.