In August and September of 1991 we observed three groups of neonatal prairie rattlesnakes (Crotalus viridis viridis) near a prairie dog town in the Sand Hills (Cherry County, Nebraska). One of these groups included at least 31 neonates and 2 postpartum females. In addition to spatio-temporal association of neonates and putative mothers, we observed a radio-tagged male prairie rattlesnake consecutively visit two natal sites, just before and just after parturition. Mean mass of neonates in two groups was below the range previously reported for this subspecies. Young-of-the-year (YOY) captured during ingress were longer and weighed more than neonates captured at birth. Feces collected from nine YOY captured at hibernacula contained pocket mouse (Perognathus spp.) remains. In contrast to other intensively studied populations, most YOY in the Sand Hills appear to feed and grow before first hibernation.