the Great Trade Route through the Mongolian Desert

At the end of the 19th century, as Japan emerged as an imperial power after the Meiji erahis army undertook an ambitious cartographic project to precisely know the territories beyond its borders. Those maps, prepared by the Imperial Japanese Army with methods that combined espionage, foreign sources and field work, were classified as state secrets and for decades remained hidden in military and university archives.

Today, those maps have revealed a fascinating route.

A forgotten runner. For centuries, the so-called Great Mongolian Route was a key artery of Eurasian tradean east-west route that crossed southern Mongolia connecting northern China with Central Asia and beyond, serving as a northern alternative to the better-known routes of the Silk Road.

Despite its historical importance, it had been blurred between travelers’ stories and scattered references, without precise cartography that would allow it to be reconstructed in detail. That gap is what is now filled through a historical work, a published study in the Journal of Historical Geography by Chris McCarthy and his colleagues demonstrating for the first time that the Great Mongolian Route was not a literary abstraction, but a perfectly structured corridor, designed to enable the regular transit of camel caravans through some of the most arid and hostile landscapes on the continent.

Military maps as secrets of the past. The researchers behind the discovery say that the key to rediscovering the Great Mongolian Route has been in the gaihōzuthose maps prepared by cartographers of the Imperial Japanese Army between the end of the 19th century and the Second World War, which systematically covered vast regions of Eastern and Inner Asia.

Conceived with strategic and classified purposes For decades, many were on the verge of disappearing after the war (there were instructions to destroy them), but some were saved quietly and ended up in university archives that little by little became accessible to the public.

Explaining the maps. The maps were not simple military sketches: they synthesized information from Chinese records, ancient Russian uprisings, and, in some cases, Japanese field work, resulting in a surprisingly accurate representation of routes, wells, monasteries, oases and geographical features key to survival in the Gobi Desert.

Confirm the map on the ground. Recent work has gone beyond the archive, touring more than 1,200 kilometers on the ground to verify to what extent those sheets coincided with current reality. The verification has confirmed about fifty nodes (from water sources to settlements, caves and sacred places) spaced at intervals of about 24 kilometers, a distance that fits exactly with the average day of a camel caravan.

Plus: the oral traditions of local shepherds, the physical traces of secular transit and the persistence of toponyms have reinforced the idea that these maps captured a refined logistical system, one in which each stop was essential to making the journey possible.

Caravans, tea and benefits. Although the main objective has been to document the infrastructure of the route, everything indicates that was parte of the historic tea trade, with Chinese goods traveling west and steppe products returning east.

Inscriptions found in caves and oases speak of journeys of up to 120 days for heavy caravans and faster journeys, of about 90 days, for urgent transports seeking extraordinary benefits. The harshness of the route did not deter the merchants, moved by the promise of “triple benefits,” a reminder that these routes were not only avenues of cultural exchange, but high-risk economic gambles.

From stories to cartography. For decades, knowledge of the Great Mongolian Route depended almost exclusively on the descriptions of the explorer and scholar Owen Lattimorewhose diagrams offered a conceptual vision of the corridor. Now, the combination of his stories with the millimeter detail of the gaihōzu transforms that diffuse image into a concrete and verifiable layout, where each lake, well or monastery has a clear function.

The result not only recovers a lost route, but shows to what extent these military maps constitute an exceptional file of landscapes, economies and ways of life just before modern transportation erased centuries of mobility caravan in the interior of Asia.

Image | McCarthy et al. 2026

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