In FY2011, USGS scientists used the passive microwave observations from the Special Sensor Microwave Imager (SSMI) on board a Defense Meteorological Satellite Program (DMSP) satellite to explore the linkages between seasonally frozen ground, climate change, and groundwater recharge in the Pacific Northwest. If the ground is frozen, less surface water can infiltrate the soil to become recharge. In agricultural regions that rely on groundwater for irrigation, small changes in recharge rates can have a dramatic effect on water supply and the region’s economy. Preliminary results show the feasibility to identify areas that are either bare and not frozen, bare and frozen, or snow-covered. These results are being incorporated into a hydrologic simulation model to better estimate groundwater recharge under a range of frozen ground conditions.