The Colville watershed (HUC 17020003) covers an area of 6,696 square miles in northeast Washington state. The hydrology of the watershed is influenced by the Colville River, which is the main tributary of the Columbia River. The area experiences a continental climate with cold winters and hot summers. The snowpack in the winter months is a critical source of surface water in the area, providing up to 60% of the annual water supply. The Colville River and its tributaries support important fisheries, including Chinook and steelhead salmon. The reservoirs within the watershed, including the Lake Roosevelt Reservoir, provide hydroelectric power and recreational opportunities. Interesting climatic trends in the region include increased temperatures and reduced snowpack due to climate change. These changes could have significant impacts on the hydrology and ecology of the watershed in the future.