Crotalus willardi silus is recognisable as it has less conspicuous markings than its sister subspecies. Its
head is brown with irregular dark spots, it has a dark
ocular band starting dark brown at the corner of the eyes and fades to grey as it reaches the end of the
supralabials and the front of the head is usually grey. It lacks the facial markings seen in other subspecies of
C. willardi.
Dorsally, the
snake is brown or red with blotched and dotted with brown markings. Its rattle is dark brown and rounded, with sharp
scales as a sheath for it, as is characteristic of the species. It is also a smaller snake, measuring up to 63.6 cm (25 in). == Diet ==