North America includes the countries of Canada, USA and Mexico, as well as Greenland ( the worlds largest island ) the Caribbean islands and the narrow isthmus of central America that joins the continent with south America. Most of the population and industry are concentrated in the northeast, which has a temperate climate. The hotter south and drier west are thinly populated and few people live in the far north physical features. Northern North America has two main mountain ranges the Rocky mountains which form a huge barrier in the west and the older wooded Appalachians in the east. North America has the most famous natural wonders. North American climate varies according to latitude, altitude, and distance from the east or west coast. North America is rich in resources, it has nearly every important mineral fertile soil suited for agriculture, huge forests of timber and access to some fine fishing grounds for thousands of years. The people of North America developed a series of advanced civilizations that traded and fought with each other over the vast plains and river valleys of the North American continent. North America's coniferous forest covers a very large area.