The article features a collection and analysis of all known historiographical information concerning the operation of the Bolgar saltpetre plant in the territory of Bolgar fortified settlement in the Spassky district of Kazan governorate. The author provides information on Russian saltpetre production in general, and introduces into scientific discourse the archival sources on the personnel of the Bolgar saltpetre plant based on confessional registers from the Assumption Church located in Bolgary village of the 18^th century. The most thoroughly analyzed cartographic material of the 18^th – 19^th centuries provides information on plant operation, the arrangement of primary production facilities, raw material sources, and other details. The author concludes that the termination of the plant began in 1673 and terminated in the first half of the 18^th century. In the mid-18^th century its operation resumed, and for instance in 1873 its personnel consisted of 380 people.