The Bering Strait is the 82-kilometre stretch of cold, foggy water that separates the Russian Far East from the Alaskan mainland. At its narrowest point, between Cape Dezhnev in Chukotka and Cape Prince of Wales in Alaska, the strait is only 82 kilometres wide. In the middle of that gap sit two small islands — Big Diomede on the Russian side and Little Diomede on the American side — separated by just 3.7 kilometres of water and by the International Date Line, which runs between them. From Little Diomede you can see Big Diomede clearly on any clear day. The time difference between the two islands is 21 hours: when it is noon on Tuesday on Little Diomede, it is 9 AM on Wednesday on Big Diomede. The strait is geopolitically the only place where the United States and Russia are within sight of each other. It is also one of the most consequential pieces of geography in human history, because for several thousand years during the most recent ice age, it was not water but dry land.
Beringia and the First Americans
During the last glacial maximum, roughly 21,000 to 14,000 years ago, sea levels were about 120 metres lower than today because of the enormous volume of water locked up in continental ice sheets. The shallow continental shelf beneath the Bering Strait was exposed as dry land. The land bridge — usually called Beringia — extended about 1,600 kilometres north-to-south, forming a substantial sub-continent connecting eastern Siberia to Alaska. Beringia was cold but ice-free in its central area, supporting steppe grassland and the megafauna that grazed it: mammoths, bison, horses, saiga antelope, and others. Bands of human hunter-gatherers from northeast Asia followed the herds into Beringia, lived in the central steppe area for thousands of years, and eventually moved south into the Americas as the ice sheets receded. Current evidence suggests humans were in the Americas by at least 15,000 years ago, possibly considerably earlier. Beringia itself flooded again as sea levels rose at the end of the ice age, separating Asia from the Americas by water around 11,000 years ago.
The Strait Today
The strait is named after Vitus Bering, a Danish-born officer in the Russian Imperial Navy who led the first European expeditions through these waters in 1728 and again in 1741. Bering died of scurvy on the return voyage of the second expedition on what is now Bering Island, off the Kamchatka coast. The Russian Empire claimed Alaska on the basis of these expeditions and sold it to the United States in 1867 for $7.2 million — about two cents an acre. The current border between Russia and the US runs through the centre of the strait, passing between the two Diomede Islands. Cape Dezhnev, on the Russian side, is the easternmost point of the Eurasian landmass. Cape Prince of Wales, on the American side, is the westernmost point of the North American mainland.
The Diomede Islands
The two Diomede Islands are remarkable for being among the few places where two nuclear-armed superpowers are within walking distance of each other (assuming the water is frozen). Big Diomede (Russian: Ostrov Ratmanova) is the larger island, with an area of about 29 square kilometres. Its population in 1948 was approximately 200 indigenous Iñupiat people; in that year the Soviet government forcibly relocated them to the mainland because of fears about contact with the American side. The island has been uninhabited by civilians ever since, used only as a Russian border guard outpost. Little Diomede, the American island, has an area of about 7 square kilometres and a population of approximately 80 indigenous Iñupiat residents who fish, hunt, and live in the village of Diomede on its western shore. The village faces directly toward Big Diomede, 3.7 kilometres away across the international border. The residents of Little Diomede cannot freely visit Big Diomede or vice versa — the border is closed even though the islanders are closely related ethnically and historically. In winter, when the strait freezes, the ice between the two islands theoretically forms a walking route, though the border is monitored by both Russian and American patrols.
The Bridge Proposal
The idea of building a bridge or tunnel across the Bering Strait has been discussed off and on for over a century. The first serious proposal came in 1892 from the Colorado governor William Gilpin, who envisioned a railway connecting the trans-Siberian system to the trans-American one. The proposal has been revived periodically since, most notably by the Russian government in various forms during the 2000s and 2010s. Engineering studies have established that a bridge or tunnel is theoretically buildable. The 82-kilometre crossing would be roughly twice the length of the longest existing undersea tunnels (the Channel Tunnel, the Seikan Tunnel). The construction cost would be enormous — estimates range from $35 billion to over $100 billion. The actual barriers to construction, however, are not engineering but political: the bridge would need to connect functioning rail networks on both sides, neither of which currently extends close to the strait, and the underlying political relationship between Russia and the United States has not in recent decades been conducive to such joint projects. The proposal is currently dormant.
Shipping and Sea Routes
The Bering Strait sees increasing commercial traffic as Arctic sea ice retreats. The Northern Sea Route — the shipping route along the Russian Arctic coast from northwestern Europe to the strait, and then south into the Pacific — has become navigable in summer months for ice-strengthened ships, and Russian and Chinese shippers have begun using it for trans-Arctic cargo. The strait itself is open year-round in some sense but is frequently blocked by sea ice in winter. The US Coast Guard maintains an icebreaker presence in the area. International Maritime Organisation rules require ships transiting the strait to follow specific designated routes to reduce environmental risk; major oil spills in the strait would be effectively unrecoverable given the cold water and remote location. The combined effects of climate change, increasing Arctic shipping, and the political tensions between Russia and NATO over the future of the Arctic make the strait one of the more strategically watched waterways of the early 21st century.
Wildlife
The Bering Strait is one of the most productive marine wildlife corridors in the Northern Hemisphere. The narrow passage concentrates currents, ice movements, and migrating species. Bowhead, gray, and beluga whales pass through the strait twice a year on their migrations between summer feeding grounds in the Chukchi and Beaufort Seas and winter calving grounds further south. Walrus haul out on sea ice in vast numbers during the open-water season. Polar bears use sea ice to access seals and walrus. Seabird colonies on St Lawrence Island and the Pribilof Islands support millions of breeding birds. The indigenous Iñupiat and Yupik communities on both sides of the strait have hunted these species for millennia and continue to do so under regulated subsistence harvests. Climate change is rapidly altering the ice conditions and timing of marine seasons in the area.
The Crossings That Have Happened
Despite the political barriers, the Bering Strait has been crossed by individual swimmers, kayakers, and adventurers multiple times. Lynne Cox, an American long-distance swimmer, swam from Little Diomede to Big Diomede in August 1987 — the first formally permitted crossing of the strait since the closure of the Soviet border. The water temperature was 7°C; Cox completed the swim in just under two hours. Soviet officials greeted her on arrival, an event treated at the time as a small thaw in Cold War relations. Various skiers and dog-sled teams have crossed the frozen strait in winter, though only some have done so with the cooperation of both governments. The crossings remain difficult to arrange legally, and most attempts in recent years have been denied permits by Russian authorities.
Why It Matters
The Bering Strait's importance is layered. Historically, it was the migration route by which the first humans entered the Americas — making it arguably the most consequential geographic feature for human prehistory. Geopolitically, it remains the only place where Russia and the United States face each other directly across a short water gap. Ecologically, it concentrates extraordinary marine biodiversity. Climatically, it sits at the centre of the Arctic warming story. Commercially, it is becoming an increasingly used shipping route. Each of these stories overlaps with the others in ways that make this remote, foggy gap of cold ocean one of the more significant patches of geography on the planet, despite the fact that virtually no one lives there.