I am in SE Alaska for the first time in about 25 years. Last time here I was not into BF. Looking at the Geology of Alaska today I think like someone mentioned, it does not point to a vegetarian being able to make the Bearing Bridge transit. Giganto is not a good candidate. .. For anything to make the transit, they had to hug the ice sheet or top it to make the passage. As those who have been here, most of SE Alaska is dozens of islands. Hugging coastal ice sheets would not get you very far unless you had boats to go island to island. Topping the glaciers is a difficult transit because the ice is very rough and goes around all the higher terrain that even to this day is not scarred by the passage of the glaciers. The peaks sticking above the glaciers are very sharp and rugged because the glaciers went around them. What ever made that transit had to eat fish or meat. I question the ability to make the transit without boats. BF is not a boat builder. Humans have for a very long time. Perhaps BF came from South America? Recent discoveries have make it likely that mankind was there long before travelers made the Bearing Bridge crossing. Certainly there is history of apes in SA. Key fossils may not have been discovered yet to give us the BF migration vector. After all the camel originated in NA and migrated the other way.