Western juniper (Juniperus occidentalis) has been implicated in causing the loss of native herbaceous plant communities and the bird and animal species that rely on them, increased soil loss and reduced infiltration.  USDA Forest Service inventory analysis indicates that since 1934, western juniper’s dominance on eastern Oregon’s rangelands has grown from 1.5 million to over 6 million acres.  In 1993, a paired watershed study was initiated in the Camp Creek drainage, a tributary of the Crooked River of central Oregon, to evaluate the impacts of western juniper removal on a site’s hydrologic function.  The study involves a paired watershed approach for evaluating changes in a system’s water budget following western juniper control.  Water budget is measured in terms of inputs (precipitation) and outputs (soil moisture, runoff, groundwater recharge and evapotranspiration).  Watershed impacts include the water budget impacts plus changes in vegetation composition and cover and erosion rates.  Juniper was removed from the treatment watershed in 2005 after 12 years of pretreatment monitoring on 2, 110 hectare watersheds.  Post-treatment vegetative responses were evaluated in 2007.  Hydrologic responses including changes in depth to ground water, spring flow, channel flow and soil moisture were assessed and conclusions suggest responses in spring flow, increased days of recorded ground water and changes in relative availability of soil moisture are a result of juniper reduction.   Precipitation received from October to May accounts for 70 percent of the annual precipitation and directly impacts actual water yields.