Well, we know that it did happen. What we don't know is how extensive it was and how far-reaching it was. Was it simply local, cross-strait traffic between families and close tribes, or were there long-distance trading relationships that stretched to China and onward?

That there was cross-strait traffic before the written record is pretty well established by oral history and archaeological evidence and has been for years. Dorothy Jean Ray's The Eskimos of Bering Strait, 1650-1898 is an older but comprehensive look at early life in the strait region. It goes into discussions about raids by the Chukchi into coastal Alaska and even as far as the Yukon River region. Archaeological evidence backs up the stories about these raids.

We also have cultural ties ─ there are linguistic links on either side of the strait. There's Siberian Yu'pik and Alaska Yu'pik, so closely related that the languages are practically intelligible. There are technological ties, too. I mentioned to you in the last question that Chukchi combat armor is stylistically very similar to that used in portions of western and southeastern Alaska. That could be a case of parallel evolution, so we can't entirely say that it's a direct technological transfer.

The most exciting evidence of prehistorical contact was found during a 2011 archaeological dig at Cape Espenberg on the northern coast of the Seward Peninsula. It was a broken cast bronze buckle, and after dating and analysis were completed, the find was written up in the October 2016 issue of the Journal of Archaeological Science.

Of course, it's been written about plenty of times in the five years between the find and the published paper, but the story is still exciting. The buckle was found attached to a piece of leather, which allowed radiocarbon dating. That leather dated to 1000-1300 AD, well before contact, and since we know that bronze was not created in Alaska, particularly not cast bronze, we can definitively state that it's evidence of long-distance cross-strait contact.

Again, what we don't know is whether this is a fragment of regular trade with China/Japan, or if this is merely a one-off artifact that was traded hand-over-hand as a unique object not representative of regular contact. The clarifying evidence might be out there, just awaiting another dig ...