Humans first migrated to North America over the Bering Land Bridge around 12,000 years ago, gradually populating the Americas as nomadic hunters and gatherers. As some settled down to farm and adapt to their environments, cities began to emerge in locations determined by surrounding land and resources, such as Montreal on an island at the confluence of two rivers, and Los Angeles which sprawled due to mild weather and available land. Waterways like the St. Lawrence Seaway connected the Great Lakes for trade but also introduced invasive species.

1. Human Environment Interaction: North America

2. Humans have been in North America for a while.Nomads first came over around 12,000 years ago from Siberia.

3. They crossed over the Bering Land Bridge or Beringia.The Bering Strait is relatively shallow. During ice ages, so much sea water would be frozen up in the ice caps that it exposed the sea floor. This created a land bridge between the two continents that nomads (people who move from place to place) crossed, most likely while hunting game.

4. From Alaska, the nomads flowed north and gradually populated the Americas.East AsiaInuit

5. Eventually people settle down and switch from a hunter-gatherer lifestyle to an agricultural one. They begin farming and raising animals.

6. They also must adapt to their surrounding environments.Eventually cities pop upWhere they are and what the land is like determines how the city develops.

7. Let’s look at each of the book’s two examples:Montreal

8. On a big island where two important rivers meet: the St. Lawrence River and the Ottawa River

9. Located here because of the rivers. Prime trading and transportation location.

10. Because the winters were cold, they developed a large underground complex known as the Underground City.

11. It has 32 km of tunnels as well as residential and commercial areas.Los Angeles

12. L.A., on the other hand, has very mild weather, so people are going to build above ground.

13. It also had lots of land and so just kept spreading out.

14. It currently has about 3.8 million people and occupies almost 500 square miles.

15. Houston covers 601 square miles and has a little over 2 million people.MovementRivers, canals, and highways, oh my.St. Lawrence Seaway

16. A canal system built to connect the Great Lakes to each other (they’re not naturally connected) and with the sea.

17. This way, ships can travel from the Atlantic to industrial centers along the Lakes, e.g. Detroit and Chicago.

18. Because the Lakes are at differing elevations, however, a lock system is used.

24. Time-Lapse Video of the Erie Canal

25. The Seaway was made for trade purposes, but there’s debate about how successful it is.

26. It’s too small by today’s standards and many parts are too shallow. Only 10% of oceangoing vessels can navigate the entire route.