Alder Lake is a reservoir on the Nisqually River just west of Mt Rainier. There are views of the mountain from a few places, especially the east end. The water is often tinted to turquoise in the summer months from the suspended "rock flour" coming from the Nisqually Glacier. The lower lake has two arms extending out. The south arm is narrow, protected from wind, and surrounded by forest, while the north arm is broader and has more pastoral surroundings.