Hokkaido's coal mines, which for years have struggled to survive amid an influx of cheap imports, have seen demand rebound as utilities grow increasingly dependent on coal-fired power plants during the nuclear crisis.
Many major domestic mines ceased production after the market was flooded with cheap and better burning foreign imports, and as coal was largely replaced by petroleum in power generation.
Mining companies find it too costly to ship coal to other parts of the country, but they continue to mine it for local customers at a time when hefty demand in China, India and other emerging nations is driving up prices.