This study, prepared by the Process Evaluation Office, Division of Systems Engineering, Fossil Energy, estimates typical capital investments, operating costs, and the required selling prices for coal produced from hypothetical subbituminous and lignite strip mines in the Northern Great Plains province. Annual production for the subbituminous mine is 4 million tons; for the lignite mines, it is 3 and 5 million tons. Wage and union welfare rates are those that went into effect under the Western Coal Wage Agreement of 1977. Costs of materials and equipment are based on first-quarter 1979 indexes. It is assumed that the mines have a 20-year life. Two selling prices for coal were determined for each mine - one based on 12-, 15-, and 20-percent returns on equity, and the other based on the same returns with a debt-equity split of 1:2 with 9 percent interest paid on debt dollars. Investments for the mines are summarized in a table.