In Oklahoma, births occur evidently in August and early September, sexual maturity is attained apparently in third year, breeding apparently is annual, fecundity (4-24 yolked follicles, mean 13) increases with female size, and the largest and oldest snakes probably are 10-15 years old (based on snakes examined at several rattlesnake roundups in Oklahoma, Fitch and Pisani 1993).

In south-central Arizona, mating occurred in spring and fall; females underwent vitellogenesis exclusively in spring, ovulated in early summer, and gave birth in August; over four years, no females gave birth more than once, indicating that reproduction is less than annual; litter sizes ranged from 2-7 (mean = 4.5) (Taylor and DeNardo 2005).