The entire population of the Wood River Valley depends on ground water for domestic supply, either from domestic or municipal-supply wells, rapid population growth since the 1970s has raised concerns about the continued availability of ground and surface water to support existing uses and streamflow. To help address these concerns, ground- and surface-water conditions in the area before and during the population growth that started in the 1970s was evaluated. This dataset denotes the boundary for ground-water analysis relating to 2006 hydrologic conditions of the unconfined aquifer. Four of the tributary canyons outlined by this boundary were not included in ground-water analysis for pre-development conditions due to lack of pre-development data in these areas.