The paper analyzes the development level of the institute of public–private partnership (PPP) in Russia’s mining complex and the partnership mechanism, within which the state, using RF Investment Fund monies, assists investors in underdeveloped areas not only in creating infrastructure but also in implementing necessary environmental protection measures. In order to analyze the properties of such a partnership mechanism, the authors have worked out economic and mathematical tools that make it possible to effectively divide spending between the state and a private investor in development of the mineral resource base. The toolkit combines integer mathematical programming and a set of predictive models that describe the functioning of a resource area. The methodology of its application is illustrated with a case study of Zabaikalskii krai, for which a program for developing polymetallic fields is being worked out based on the PPP mechanism; the sensitivity of its decisions to changes in the main partnership parameters is analyzed. The results of numerical experiments confirm the rationality of using this mechanism in an underdeveloped area. They show that, in addition to a coherent approach to assessing the specific amount of funds to be allocated to infrastructural and environmental projects, an important role is played by transaction costs accounting, the level and structure of which affect the effectiveness indicators achieved not only by a private investor, but also by the state.