The book is a reading book, reference work, and picture book all in one, covering nearly all aspects of a key industry from around 1860 to 1990. The catalog describes 477 mines: detailed historical data on the development of each mine from the Middle Ages to the present, names of the mines and shafts, production capacity, workforce, technical innovations, initial operations, architectural features, special events, and monument and environmental protection. The introduction provides a history of coal mining in the Ruhr area from its early days to the present.