What is the distance between the United States and Russia at the closest point?

The narrowest distance between mainland Russia and mainland Alaska is 51mi (82 km). However, in the body of water between Alaska and Russia, known as the Bering Strait, there lies two small islands known as Big Diomede and Little Diomede. Big Diomede is owned by Russia while Little Diomede is owned by the US. The islands are separated by the maritime border of the two countries, which coincides with the International Date Line, about 1.2 mi (2 km) from each island, at 168°58'37"W. At their closest points, the two islands are 2.4 mi (3.8 km) apart.

The International Date Line puts Big Diomede twenty one hours ahead of Little Diomede so Big Diomede is also referred to as "Tomorrow Island" and Little Diomede is called "Yesterday Island".

The stretch of water between these two islands freezes during the winter so one could technically walk from the US to Russia on this seasonal sea ice.

The border separating the two islands was created in 1867 when the United States purchased Alaska from Russia. Residents traveled freely between the islands until the Cold War when the border was closed and nicknamed the “ice curtain".