Matsumoto Kaido

Matsumoto Kaidō: The Salt Road Through the Himekawa Valley

For roughly three centuries, oxen and porters hauled sacks of salt up a steep mountain track from the Japan Sea coast at Itoigawa toward the landlocked towns of central Shinano. That track was the Matsumoto Kaidō, a 120-kilometer trade route along the Himekawa valley that the people of the region simply called the Shio no Michi, the Salt Road. In 2002 a surviving section within the city of Itoigawa, in Niigata Prefecture, was designated a National Historic Site, and the protected area has since been enlarged twice, most recently in March 2025.

The designated route is less a single monument than a corridor: about five kilometers of original road bed, together with clusters of stone Buddhas, the foundation of a roadside teahouse, and the remains of lodgings where porters once spent the night. Walking it today gives a fairly direct sense of how goods and people moved between two very different worlds, the fishing coast and the mountain interior.

A Side Road That Carried a Region

The Matsumoto Kaidō was a branch route of the Hokurikudō, the main highway running along the Japan Sea coast. It went by several names. Travelers in Shinano, present-day Nagano, called it the Itoigawa Kaidō; elsewhere it was known as the Shinshū Kaidō or the Chikuni Kaidō. The Itoigawa end was the one most closely bound up with salt.

Salt cannot be produced inland. The communities of the Matsumoto basin and the valleys around it depended on supplies hauled in from the sea, and the most practical source was the coast at Itoigawa, directly north across the mountains. Northbound from the coast went salt and dried marine products; southbound from Shinano came soybeans, tobacco, medicinal herbs, cotton, and hemp. Account books kept at the domain checkpoints record how lopsided the traffic was. Between the twelfth month of 1858 and the eleventh month of 1859, the volume of goods heading south into Shinano outweighed the return cargo by roughly ten to one, and most of that southbound load was salt and seafood.

Carrying it was brutal work. The porters, known as bokka, and the ox-drivers called ushikata moved an average of about fifty kilograms per load and covered some thirty kilometers a day. The route crossed passes with elevation changes of a hundred meters or more; in places near Lake Shiraike the climb approached three hundred. There were no shortcuts.

Uesugi Kenshin and the Legend of Salt

The road has a place in one of the better-known stories of Japan's Warring States period. Uesugi Kenshin, the daimyo who controlled Echigo, the province that is now Niigata, set up checkpoints along the route and organized a system of licensed wholesalers, the Shinshū toiya, to manage the trade while keeping the salt itself in free circulation. His rival Takeda Shingen, whose territory in Shinano had been cut off from its Pacific-side salt supply by an alliance of hostile provinces, is said to have received salt from Kenshin rather than being starved of it.

The episode is the origin of the Japanese expression teki ni shio o okuru, "to send salt to an enemy" — that is, to aid an opponent in genuine need rather than exploit a weakness. How literally the story should be taken is debated among historians, and it is best understood as tradition rather than documented fact. The road itself, however, was real, and the trade it carried was tightly regulated. Six wholesale houses were licensed in 1604, and the checkpoint system survived until 1869, when the barriers and the wholesalers alike were abolished in the early Meiji reforms.

Why the Road Survived

A new carriage road opened in 1892, and the old mountain track lost its purpose as a trade artery. Ordinarily that would have been the end of it. What kept the Matsumoto Kaidō intact was ordinary use. Stretches of it continued to serve as forestry roads and as everyday paths between hamlets, so the road bed was neither paved over nor left to erosion.

By the late twentieth century the route had become a subject of study. The Niigata prefectural board of education carried out a survey of historic roads in 1990, and a maintenance project funded by the national Agency for Cultural Affairs ran from 1992 through 1999. Of the roughly twenty kilometers of the kaidō within Itoigawa, about ten kilometers through the Ōno and Nechi districts still hold their old form well. The five kilometers whose historical boundaries could be confirmed, together with the associated stone monuments and ruins, make up the designated Historic Site. The recognition rests on what the road shows about transport infrastructure and about the working life of the region.

What to Look For on the Trail

The single most distinctive feature is the utō. Centuries of feet and hooves wore the path down into a deep, U-shaped trench, in places well above head height on either side. The shape was not an inconvenience the travelers merely tolerated. A sunken, walled track is sheltered from wind, holds less snow, and gives oxen a clear line to follow. The utō near Ōno is regarded as an especially fine example, and it is a central reason for the road's designation.

Stone marks the route at intervals. There are clusters of carved Buddhist figures: rows of six Jizō, horse-headed Kannon associated with the safety of pack animals, roadside deities. Old signposts survive too, cut with directions in worn script; one points right to Inokuchi village and left to Shinshū. Near a small hall stands the Kanpa Jizō, a stone figure once believed to cure skin ailments. Beside it is a rock called Kabuto-iwa, the "helmet rock," named from a tradition that one of Kenshin's senior retainers rested his helmet there.

Other traces are quieter. The foundation of the Hinata teahouse marks a place where travelers once stopped to rest; it was built around 1824 to replace two porters' lodgings destroyed by a massive avalanche off Mt. Tokura. Elsewhere, simple graves hold travelers who collapsed on the road and were buried by the people of the nearest hamlet, a plain reminder of how hard the crossing could be.

Walking the Route Today

The Itoigawa section is most often walked as a day hike between the coast and Nechi, a distance of roughly ten kilometers. Both ends are reachable by rail. JR Itoigawa Station sits near the salt route's coastal starting point, and the JR Ōito Line runs inland to Kubiki-Ōno and Nechi stations. A local bus on the Nechi line connects Itoigawa Station with the inland hamlets, which makes a one-way walk straightforward to plan.

The trail is well signed, with frequent markers, and the climb over Nakayama Pass, the stretch where the utō is best preserved, is the scenic highlight, with views toward the Japan Sea on one side and the mountains of the old Echigo–Shinano border on the other. Two cautions matter. The pass area is bear country, and signboards along the way say so; carrying a bell and making noise is sensible. The route on the western side of the Himekawa is difficult or impassable under snow from December through May and overgrown in high summer, so for that section a local guide is strongly recommended, both for route-finding and because the terrain is hard to read. Every year on May 2, Itoigawa holds a walking event along the salt road from the coast to Nechi, timed to lead into the larger Shio no Michi festival held in the Nagano villages just to the south.

Around the Salt Road

In the town of Itoigawa, the coastal end of the route is marked by a road monument, a small plaza, and an ox-tethering stone in the grounds of a temple, where pack animals were once tied during halts. The Shio no Michi museum, housed in an old farmhouse along the way, displays the tools, clothing, and packing gear of the bokka and ushikata.

Itoigawa is also a UNESCO Global Geopark, and the route passes close to several places worth a detour. The Fossa Magna Museum explains the great geological fault line that runs through the region, the same valley corridor the salt road follows, and displays jade, which was worked here in prehistoric times. Nearby, the Chōjagahara site preserves a major settlement of the middle Jōmon period. Miyama Park, on the high ground above the city, is a fine vantage point in its own right.