Dorsally they have a pattern of dark brown or black crossbands on a yellowish brown or grayish background. The crossbands have irregular zig-zag edges, and may be V-shaped or M-shaped. Often a rust-colored vertebral stripe is present. Ventrally they are yellowish, uniform or marked with black.
In the northern parts of their range, timber rattlesnakes live in forested rocky hills. In the southern parts of their range these snakes are found in uninhabited swampy areas