Who were the first humans to reach North America? When did they arrive? How did they get here? Some evidence suggests that they walked across the land bridge that once connected Siberia and Alaska. A growing number of archaeologists now believe that at least some, if not most, of our forefathers arrived by boat along the northwest coast of North America. They may have originated from Japan or Southeast Asia and stuck to the shorelines. A few archaeologists note similarities between early North American stone tool technology and specimens found in Europe. They speculate that early humans reached the continent by boat, crossing the frigid North Atlantic waters. With archaeological field photographs and realistic illustrations by Richard Hilliard, David L. Harrison explores the various theories of North America's first people. He shows how scientists are like detectives investigating mysteries that took place more than one hundred centuries ago. Includes maps, glossary, sources, index.