With increased use being placed on natural gas, electricity, petroleum, and coal, alternative forms of energy have been sought to help release the pressures being placed on these resources. Geothermal energy is one of the major alternative forms. In portions of Boise, geothermal resources have been utilized for many years for heating of homes and several state office buildings. Recent investigations in the Boise area have shown that hot water is abundant all along the Boise Foothills. This report discusses two areas showing good potential for future geothermal development. These areas are the Dry Creek Valley and the area between Pierce Gulch and Polecat Gulch. Both areas have water temperatures exceeding 37.8°C. In the Boise area it is found that zones of hot water are associated with some type of structural control. The hot water zones associated with the Dry Creek Valley and the Pierce-Polecat area were found to be located at or near the intersection of major linears mapped along the Boise Foothills. These linears reflect a zone of weakness at depth in the rock allowing warm water to migrate upward from the granitic rock of the Idaho batholith below. By mapping all known fault and linear patterns in the area, it is possible to correlate these zones of weakness with areas of hot water. At the intersection of two or more linears, where fracturing is greatest, the majority of geothermal water has been located