The Meiji government nationalized the Miike Coal Mine in 1873. The government modernized the facilities and made the Oura, Nanaura, Miyaura, and Katsudachi pits the primary mining sites. After the mine was sold to Mitsui in 1889, it was managed by Dan Takuma. With the opening of the Miyanohara and Manda Pits in the Meiji era (1868-1912), as well as the Yotsuyama Pit in the Taisho era (1912-1926), Miike Coal Mine soon became the largest mine complex in the country. By the time coal mining reached its peak in the early 1900s, it was the backbone of Japan’s industrial development. By the second half of the 1900s, however, mining efficiency began to decline and a shift from coal to oil as the main source of energy occurred. This eventually resulted in the closure of Miike Coal Mine in 1997.