A Bering Strait crossing is a hypothetical bridge or tunnel that would span the relatively narrow and shallow Bering Strait between the Chukotka Peninsula in Russia and the Seward Peninsula in the U.S
Place for the bridge, showing the Siberian ghost town of Naukan as its western terminus.
The Mammut americanum (American mastodon) became extinct around 12,000–9,000 years ago due to human-related activities, climate change, or a combination of both. See Quaternary extinction event and Holocene extinction.