The Montana geothermal database includes 267 distinct thermal wells and springs (Metesh, 1994). Sixteen resource areas and more than 100 isolated thermal occurrences are reported. Thermal wells and springs occur throughout all areas of Montana but mainly (152 of 267) in the western third of the state (the Northern Rocky Mountains). The plains of the eastern two-thirds of the state host 115 of the 267 thermal sites. About 77 percent of the geothermal sites have measured water temperatures less than 40°C; but, 12 percent have temperatures greater than 50°C. Metesh (1994) identified five geothermal resources collocated with communities and recommended them as priority study areas needing geophysical exploration and deep drilling (1 area), detailed temperature, fluid chemistry and a feasibility study (1 area), deep drilling and a feasibility study (1 area), and resource studies (2 areas).
Metesh, J., 1994. Geothermal Resources of Montana, Montana Bureau of Mines and Geology, Technical Report to Oregon Institute of Technology, Geo-Heat Center, 30 p.