The usual longest-route length of the Siachen Glacier is 76 km.
The 76-kilometre figure measures the glacier along its longest route, following the main ice flow in the way geographers commonly measure a river from its source. A different measurement from Indira Col gives about 70 kilometres, which explains why shorter figures sometimes appear in reference works. For standard trivia and general descriptions, however, 76 km is the established answer.
Siachen descends from about 5,753 metres at its head near Indira Col to roughly 3,620 metres at its terminus. It is the longest glacier in the Karakoram and one of the longest glaciers outside the polar regions. Including its tributaries, the broader glacier system covers about 700 square kilometres.
The glacier’s length is often confused with the lengths of nearby Karakoram glaciers. The Biafo Glacier, for example, is about 63 km long, while Tajikistan’s Fedchenko Glacier is commonly cited at about 77 km and is slightly longer in the non-polar world.