The study described in this report is an appraisal of water resources in Grand Teton National Park where hydrologic data are needed for planning water supplies for public use. Water is used in the park for public-water supplies at National Park Service facilities, for commercial and domestic use at guest ranches and private residences, and for irrigation. Public-water supplies in the park utilize both surface and ground water. Some of the surface-water sources are in areas of heavy use by park visitors. Public-health requirements are that only ground water, if adequate in quantity and quality, should be used for public-water supplies in such areas.