The Au Sable Watershed (HUC 04070007) covers an area of approximately 1,137 square miles in northern Michigan. The Au Sable River, a designated National Wild and Scenic River, flows through the watershed and is a popular destination for recreational activities like fishing and kayaking. The area has a humid continental climate, with cold winters and warm summers. The watershed is characterized by a significant snowpack during the winter, which gradually melts in the spring and delivers large volumes of water to the river. Reservoirs in the area are primarily used for hydroelectric power generation, and their water quality is monitored regularly. Overall, the Au Sable Watershed is an important ecological and recreational resource in northern Michigan, and efforts are underway to ensure its protection and sustainability for future generations.