Across
- 1. vast grassland of central north america that is largely treeless
- 4. a group of five freshwater lakes of central north america between the united states and canada
- 6. winds that blow from west to east
- 10. a person with no permanent home who moves from place to place according to season in search for food
- 11. a major mountain system of the united states and canada, extending 3,000 miles from alaska to new mexico
- 13. permanently frozen ground
- 14. the line of the highest points in north america that marks the separation between rivers flowing east and west
Down
- 2. one of two major mountain chains in the eastern united states and canada
- 3. canada's longest river
- 5. a land bridge thought to have connected what are now alaska and siberia
- 7. america''s most important deepwater ship route, completed in the 1950 as a joint project of the united states and canada
- 8. a section of a waterway with closed gates where water levels are raised or lowered
- 9. a northern part of the interior lowlands that is a rocky, flat region covering nearly 2 million sq miles
- 12. a large subtropical swampland in florida of about 4,000 sq miles