The research evaluated the trends and changes in land cover and river discharge in the Upper Columbia River Wetlands using remote sensing and hydroclimatic data. The river discharge increased during the peak flow season, resulting in a positive trend in the open-water extent in the same period, whereas open-water area declined on an annual basis. Furthermore, since 2003 the peak flow has occurred 11 d earlier than during 1903–1928, which has led to larger discharges in a shorter time.