Development of geothermal plants, as all other energy facilities, may have significant economic impacts on local and regional economies. Often the magnitudes of these impacts will be of great interest to both environmental and economic development planners. Because of their availability and relative ease of use, input-output models are often used to estimate selected economic impacts arising from resource development. This paper demonstrates the methodology for two case studies of potential development of geothermal facilities of 100 MW average capacity in the United States Pacific Northwest, in order to highlight the effects of different local economic structures. Results indicate that geothermal development can lead to significant economic impacts at the local level.