<P> Three countries (Canada, the United States, and Mexico) make up most of North America's land mass; they share the continent with 34 other island countries in the Caribbean and south of Mexico . </P> <P> The Great Plains is the broad expanse of prairie and steppe which lies east of the Rocky Mountains in the United States and Canada . The narrow plains in the Mexican coast and the savannas of the Mississippi are analogous to, respectively, the Patagonian steppes and the pampas of the Piranha, Paraguay, and Rio de la Plata . Thus the Appalachians and the mountain chains of Brazil are regarded as creating similar interruptions to the plains community . </P> <P> North America extends to within 10 ° of latitude of both the equator and the North Pole . It embraces every climatic zone, from tropical rain forest and savanna on the lowlands of Central America to areas of permanent ice cap in central Greenland . Subarctic and tundra climates prevail in north Canada and north Alaska, and desert and semiarid conditions are found in interior regions cut off by high mountains from rain - bearing westerly winds . However, most of the continent has temperate climates very favorable to settlement and agriculture . Prairies, or vast grasslands cover a huge amount in mountain ranges . </P> <Table> Greatest Snowfalls <Tr> <Th> </Th> <Th> Places </Th> <Th> Date </Th> <Th> Inches </Th> <Th> Centimeters </Th> </Tr> <Tr> <Th> 24 hours </Th> <Th> Silver Lake, Colorado </Th> <Th> April 14--15, 1921 </Th> <Th> 76 </Th> <Th> 195.6 </Th> </Tr> <Tr> <Th> 1 month </Th> <Th> Tamarack, California </Th> <Th> January 1911 </Th> <Th> 390 </Th> <Th> 991 </Th> </Tr> <Tr> <Th> One storm </Th> <Th> Mt . Shasta Ski Bowl, Calif . </Th> <Th> February 13--19, 1959 </Th> <Th> 189 </Th> <Th> 480 </Th> </Tr> <Tr> <Th> One season </Th> <Th> Mount Baker, WA </Th> <Th> 1998--1999 </Th> <Th> 1, 140 </Th> <Th> 2, 895.6 </Th> </Tr> </Table>

What is a special geographic characteristic of central america