In the Soviet Union, the areas with the highest geothermal gradient are found in the region of Kamchatka, in the Kuriles, and in western Turkmenia. Test drilling in Kamchatka has produced hot water at a temperature of 200/sup 0/C from a depth of 100-300 m. If a pressure of 300-400 kPa is maintained, the wells can bring the fluids to the surface as a two-phase mixture of steam and hot water. In 1961, plans were being made for the construction of a 12 MW power plant and several greenhouses. Other heat sources were being developed to heat the city of Petropavlovsk. In the northern Cauacasus, hot water is encountered only at depths greater than about 2.5 km, but the quantity available is sufficient to provide the heating needs of several major cities. In the Republic of Daghestan, test drilling has revealed hot water sources which are pressurized to 1.6 MPa, and which produce at a rate of 100 m/sup 3//h. Enormous geothermal energy resources are located in artesian reservoirs beneath western Siberia, over an extent of 3 million km/sup 2/.