The Prairie Rattlesnake has broad blotches anteriorly, but narrow and joining with the lateral markings to form crossbands near the tail. The snake is usually greenish gray, olive-green, or greenish brown in color, but sometimes light brown or yellowish. The 33-35 dark brown blotches are narrowly bordered with white. The Prairie Rattlesnake also has two oblique light lines on the head, the one behind the eye passes above the corner of the mouth. The sex of the snakes is determined by probing.
Males have a hemipenis.
The two or three most recent rings that were formed are black.