The Cascades frog has a green to brown color on its back and a light yellow on its throat and belly. A range from a few to about 50 gray spots are located on its back. Depending on the situation, the spots may change color from the lighter gray/brown to a darker black spot. The colors on the frog's back are also used to attract mates. The shape of the frog's head is most commonly an oval with the mouth coming out to a slight specific point. Adult frogs range from 50 to 65 mm in length.