A rail crossing of the 51-mile-wide Bering Strait between Alaska and Russia is certainly not a new dream project—the idea dates back as far as the late 1800s. Since then, numerous railroad magnates, engineers and even heads of state have proposed bridge and tunnel schemes to link the Asian and North American continents. 

In recent years, a tunnel running underneath the 161-ft-deep channel has been the preferred option. In 2011, the Russian government was rumored to have greenlit $65 billion in funding for a tunnel as part of a plan to extend its rail network to the eastern tip of Siberia by 2030. While no specific details for the tunnel have surfaced, the rail extension has been constructed as far east as the city of Yakutsk.

A 64-mile tunnel proposal is currently being promoted by InterBering LLC, an Anchorage-based private firm that spearheads investment in the crossing. The tunnel would intersect with two islands in the center of the strait to allow for ventilation and construction access. Existing tunnel boring machine technology would be employed to construct twin 16.5-meter-dia tunnels for cargo and passenger rail, plus a 7-meter-dia emergency access and maintenance tunnel in between.

InterBering founder Fyodor Soloview, a dual citizen of Russia and the U.S., says that while tunneling costs could approach $35 billion, it will actually be much cheaper and easier to construct than the overland rail networks that approach the tunnel. The challenges of constructing thousands of miles of rail over permafrost could result in a price tag that exceeds $1.3 trillion, he says. Some cost savings could come from utilizing approximately 55 million cu yd of spoils from the tunnels—mostly basaltic gravel—as railway base.

But for now, the main impediment to the crossing project isn’t cost or engineering, but the strained relations between the U.S. and Russia over the Ukraine crisis, says Soloview. He is currently lobbying the Russian government on the economic benefits of the tunnel plan and the opportunity it presents to improve relations with the U.S.

In May, Chinese media outlets reported that China was pursuing its own tunnel scheme. Rail expert Wang Mengshu, a professor with the Beijing Jiaotong University's School of Civil Engineering, was quoted in the Beijing Times as saying that Chinese officials were considering the construction of a high-speed rail line connecting China and the U.S., via nearly 8,100 miles of track also passing through Siberia and Canada. As part of the plan, an approximately 120-mile tunnel would be built using existing technology underneath the strait.

Critics question the economic viability of any Bering Strait crossing, saying that it’s unclear that there would be any time or cost savings over existing shipping or passenger options. However, on Oct. 14, China agreed to invest $10 billion to develop and build the first high-speed rail line in Russia. The 478-mi-route from Moscow to Kazan could signal the first step in China’s larger rail ambitions.