Drawing from the economic, political, and security records of the Kế Bào Coal Company – one of the first two large-scale French coal mining companies established in Tonkin – this chapter tracks the rise and fall of the company and offers a labor, social, and racial history of the many pioneers of the coal frontier, such as the Chinese and Vietnamese migrant coal mine workers, the Vietnamese convicts, and the French personnel. By situating the history of large-scale coal mining in Kế Bào within the regional context of the Sino-Vietnamese borderland and the global coolie trade of the nineteenth century, this chapter illustrates the risks and precarities of coal mining along a remote maritime coal frontier in the early days of French colonialism in Tonkin. Specifically, it highlights the perils of financial miscalculation, labor mismanagement, overoptimistic and incomplete geological surveys, and the environmental and ecological challenges of extracting coal in a tropical landscape unfamiliar to Europeans, all of which contributed to the company’s downfall.