Baikal-Amur Magistral in green; Trans-Siberian line in red

The Baikal-Amur Mainline (Russian Байкало-Амурская Магистраль, Baikal-Amur Magistral, BAM) is a railway line in Russia. Traversing Eastern Siberia and the Russian Far East, the 4,234 km (2,305 mile) long BAM runs about 380 to 480 miles north of and parallel with the Trans-Siberian railway. The route of the present-day BAM was first considered in the 1880s as an option for the eastern section of the Trans-Siberian railway. BAM departs from the Trans-Siberian railway at Taishet (Tayshet), then crosses Angara river at Bratsk, crosses Lena river, proceeds past Severobaikalsk on the northern tip of Lake Baikal, past Tynda and Khani , crosses the Amur River at Komsomolsk-na-Amure and finally reaches the Pacific Ocean at Sovetskaya Gavan.

BAM was built as a strategic alternative route to the Trans-Siberian Railway, especially to the vulnerable sections which are close to the border with China. The section from Tayshet to Bratsk was built in the 1930s. Most of the Far Eastern section was built during the years of 1944-1946, mainly by the gulag prisoners, including German and Japanese prisoners of war, of whom possibly as many as 150,000 died. In 1953, following Stalin's death, virtually all construction work on the BAM stopped and the line was abandoned to the elements for more than twenty years. In March 1974, Soviet General Secretary Leonid Brezhnev stated that a new BAM project would become a huge Komsomol undertaking. In September 1984, a "golden spike", akin to one used in Utah in 1867, was hammered into place, connecting the eastern and western sections of the BAM. The Western media was not invited to attend this historic event as Soviet officials did not want any questions asked about the line's operational status and working conditions of the construction workers. In reality, only one third of the BAM's track was fully operational at the time of opening, and forced labor was still widely used.

BAM was finally declared complete in 1991.