Since then the collapse of small farming on the East Coast has allowed millions of acres to return to nature. When New York State surveyed itself in 1875, the six counties that make up the lower Hudson Valley—Columbia, Dutchess, Greene, Orange, Putnam, and Ulster—contained 573,003 acres of timberland, covering about 21 percent of their total area. A hundred years later trees covered almost 1.8 million acres, more than three times as much.
