NORTH AMERICA The continent of North America extends from the Arctic Circle to the Tropic of Cancer, from the Pacific to the Atlantic Ocean. West of the chain of the Rocky Mountains is the desert of Arizona and Nevada, still further west the Sierra Nevada mountains, to the east the Great Plains, the Great Lakes, the valleys of the Mississippi and the Ohio and the Appalachian Mountains. To the south is Mexico. Forty per cent of Canada is covered with forests.
Oil, gas and mineral resources are found in many areas, which explains the many big industries in the USA and Canada. Today, wheat, corn and fruit are grown extensively and fishing is a major industry in Canada. Mining, industry and extensive agriculture have been developed only in the last years by immigrants from Europe, Africa and China. But there were people who had been living in North America for thousands of years before the Europeans learnt of its existence.