Native American Migration

Native Americans have to have gotten to North America somehow, and to get here, they would have to cross the Bering Strait.  The three main theories on how Native Americans got to what is now called Washington are that there was once a land bridge connecting Siberia and Alaska (land bridge theory), the Bering Strait was frozen and created an ice bridge (ice bridge theory), or the water was receded enough so that the continental shelves were exposed enough for the Native Americans to walk across (continental shelf theory).  I think that the most believable theory is that there was once a land bridge connecting Siberia and Alaska (land bridge theory).

According to Lambert's Washington: A State of Contrast, the ocean level was several hundred feet lower than it is now.  That means that there could potentially be a land mass hundreds of feet below the surface of the ocean connecting Siberia and Alaska.  Scientists also discovered huts, fire pits, and ancient skeletons on the ocean floor in the Bering Strait.  That means that Native Americans were traveling across the land bridge in the Bering Strait thousands of years ago.

Image from Wikipedia