Mase River and Sanjūgama Gorge
The headwaters of Mase River collect inside the Shirakami Sanchi core area and the river flows down out of the mountains into the Sea of Japan just north of the town of Happō. In its descent from the mountains, the river has eroded the land into a steep gorge with many twists and turns around large rock formations.
Sanjūgama Gorge’s name comes from a local story about the river. Most towns in the area around the mountains have been logging towns for much of their history. Before the modernization of Japan in the late 1800s, cut logs were transported by floating them downriver to the sea. Woodcutters harvesting lumber in nearby Hachimori would divide the logs into pieces and pile them into stacked groups. Each piece was about one meter long, and they were bundled together into groups called kama, literally “pots.” They then threw the logs into the river to be collected farther downstream. One day, workers downriver noticed that not all the expected wood had arrived. They traveled upstream to find that 30 “pots” worth of wood had been obstructed or smashed by the boulders along this stretch of river. They then named the gorge sanjūgama, or “thirty pots,” for the amount of wood lost.