The Middle Fork John Day Watershed (HUC 17070203) covers an area of approximately 1,870 square miles in the Blue Mountains of Oregon. The watershed is a critical source of water for agriculture, wildlife, and communities downstream. Hydrologically, the area is characterized by a network of streams and rivers that originate from the Blue Mountains and flow into the John Day River. The watershed receives significant snowfall during the winter months, which contributes to the snowpack that feeds the streams and rivers during the spring and summer. The surface water in the watershed contains a mix of constituents, including sediment, nutrients, and metals, which can impact water quality. The area is also home to several reservoirs, including the Phillips Reservoir and the Olive Lake Reservoir. Interesting climatic trends include fluctuations in snowpack and precipitation levels, which can impact water availability and quality in the watershed.