Production (short tons) 1973 7,106,000 1972 6,718,000 1971 6,793,000 1970 5,471,000 1969 3,369,000 Steam Coal Steam coal derives its name from its primary historical useit is burned in the process of converting water to steam, which in turn provides the energy to drive electric generators and other machinery. Supplementing this traditional use, technology exists to convert the energy content of this coal to substitute natural gas. The Navajo mine, located on the Navajo Indian Reservation in the Southwestern area of the United States, represents Utah's most substantial interest in steam coal. The mine has operated since 1963 to fuel the Four Corners Power Plant, an important source of electricity for the region. Fuel supply contracts with the power plant owners extend to the year 2004. This plant, which is today owned by a group of six utility companies, began as a two generating unit development with a rated capacity of 350,000 kilowatts. Three units added subsequently have raised that capacity to 2,085,000 kilowatts and corresponding increases in the requirement for coal have made the Navajo mine the largest coal mine in the United States. Deliveries in 1973 were at a record level of 7.1 million short tons. Of the 1.1 billion tons of coal at the Navajo mine recoverable by strip mining methods, less than one-third is committed under these agreements. The balance of the Navajo mine reserves has been conditionally committed to two utility companies as an energy supply for as many as four substitute natural gas (SNG) plants. These plants will convert the coal into pipeline quality gas for use in the southern California area. It is expected that each of these plants will produce 250 million cubic feet of gas per day and will require annual coal purchases of approximately 9.6 million tons. With prompt acceptance of the program by appropriate governmental agencies, the first unit is expected to commence operation by 1978. Eight miles north of the Navajo mine, Utah operates the San Juan mine as a contractor for Western Coal Company which controls strippable coal reserves near a new power plant owned by two utilities. Deliveries from this operation commenced in April 1973 and shipments for the year totaled 263,000 tons. Reserves near Craig, Colorado and Kanab, Utah comprise the balance of Utah's proven steam coal holdings. Approximately one-half of the Craig reserves are dedicated to a power plant scheduled to begin operations in 1978. Steam coal has long played an essential role in satisfying electrical energy needs. Growing demands for all forms of energy, coupled with diminishing supplies of other domestic fuels, are expected to bring coal into a position of even greater prominence in the years ahead. At the Navajo mine in New Mexico, U.S.A., a 40-cubic yard (31-cubic meter) walking dragline moves overburden 24 hours a day to expose coal which will be mined and delivered to a nearby power plant. 4