"As two of the rarest metals on Earth, gold and silver have amazed humans for centuries. People have searched the world for silver and gold, hoping to fill their pockets with the shiny metals. And yet during all of human history, only enough gold has been extracted to fill two Olympic-sized swimming pools. And not every aspect of the metals is pretty. Mining gold and silver comes with many environmental consequences. The countries of North America have always had plentiful natural resources. But the exploitation of these resources comes at a cost, and in certain cases, some have wondered if that cost is too high. North American Natural Resources explores all facets of this vital aspect of our economy. Readers will investigate the natural history, human use, technology, environmental impact, and economic significance of the most significant resources on the continent"--Back cover.