


Size and shape: Usually just under two feet long, strong and cylindrically depressed body, narrow neck, abdomen thick, tapering tail.
Head: Broad, flat and round-snouted, with the center-toothed (or keeled) scales; forward-set eyes big enough with a vertical pupil (like the people of southwestern rattlesnakes); special supraorbital horns (which are not always present in all populations or even individuals); hinged hollow fangs that snap into position when the snake opens its mouth to bite.
Color and pattern: yellow, brown, reddish-gray in color, often matching the color of the soil surface; darker and more or less rectangular patch along the back.
Head: Broad, flat and round-snouted, with the center-toothed (or keeled) scales; forward-set eyes big enough with a vertical pupil (like the people of southwestern rattlesnakes); special supraorbital horns (which are not always present in all populations or even individuals); hinged hollow fangs that snap into position when the snake opens its mouth to bite.
Color and pattern: yellow, brown, reddish-gray in color, often matching the color of the soil surface; darker and more or less rectangular patch along the back.