The California Gold Rush of the mid-1800s transformed the United States population as gold seekers ventured out to the West Coast in search of the precious metal in the Golden State's rivers and creeks. Nearly two centuries later, torrential rainfall in California this past winter has helped jumpstart a new gold rush of sorts, with a so-called "flood gold" grabbing the attention of treasure hunters. Gold is heavy, so it takes a lot of water power to wash it downstream. A series of atmospheric ri