What is the Ashio Copper Mine?
The Ashio Copper Mine refers to Mt. Bizen-Tateyama, located in the heart of Ashio Town. Although Ashio Town is surrounded by numerous mountains, copper-bearing ore was found only in this mountain.
In pursuit of ore deposits, miners excavated an extensive network of tunnels inside the mountain, reaching a total length of approximately 1,234 kilometers and spanning a vertical range of about 1,000 meters.
The History of the Ashio Copper Mine
Year | Event |
---|---|
1877 (Meiji 10) | Ichibee Furukawa acquires the Ashio Copper Mine. |
1881 (Meiji 14) | A rich ore vein, the Jinbo no Naori, is discovered in the Takanosu Pit, which marks a turning point toward improved productivity. |
1883 (Meiji 16) | Ashio’s copper production increases, becoming the largest in Japan. Naoribashi Smelting Branch, Honzan Hospital, and Tokyo Honjo Copper Smelting Plant are established, and major road improvements begin in Ashio Town. |
1884 (Meiji 17) | The Honguchi Pit opens. A high-grade ore vein, Yokomabu Great Naori, is discovered in the Honguchi Pit, securing Ashio’s position as Japan’s leading copper producer. |
1885 (Meiji 18) | Excavation of the Tsudo Pit begins. |
1887 (Meiji 20) | A large forest fire breaks out in Matsuki Village. |
1890 (Meiji 23) | Severe flooding of the Watarase River exacerbates mining pollution damage. |
1896 (Meiji 29) | The Tsudo Pit is completed. |
1897 (Meiji 30) | Afforestation efforts commence in the mountains surrounding the mine – an initiative that continues to present day. |
1897 (Meiji 30) | The Tokyo Mining Bureau orders Ashio Copper Mine to undertake pollution control measures. |
1901 (Meiji 34) | Shozo Tanaka resigns from his position as a member of the House of Representatives. He attempts to submit a direct petition to Emperor Meiji but is prevented from doing so. |
1902 (Meiji 35) | The Ashio Typhoon hits the region. |
1903 (Meiji 36) | Ichibee Furukawa passes away. His adopted son, Furukawa Junkichi (biological son of Mutsu Munemitsu), assumes the management of the mine. |
1906 (Meiji 39) | Yanaka Village is abandoned. Nikko Copper Electrolyzing Refinery begins operations. |
1907 (Meiji 40) | The Ashio Riots occurs. Most mine facilities are destroyed by fire. |
1912 (Meiji 45) | The Ashio Railway (from Kiryu Station to Mato Station, now the Watarase Keikoku Railway) opens. |
1956 (Showa 31) | The installation of the Furukawa/Outokumpu flash smelting plant is completed, effectively resolving the sulfur dioxide emission issues. |
Four Major Construction Projects of Ashio Copper Mine



