Channel catfish, Ictalurus punctatus (Rafinesque), from Lake Sharpe, a 22,600-ha reservoir on the Missouri River in South Dakota, showed little change in abundance during the first 8 yr of impoundment, 1964–1971. All year classes from 1953 through 1969 were represented in gill net catches. Mean lengths of fish at a given age averaged 20% less in 1971 than in 1964. Average annual survival rate was calculated to be 69% from age VI to XVI. Some females attained sexual maturity at age VII, but only 50% were mature at age XIV. Less than 10% of the females 437 to 489 mm total length were mature; all females over 593 mm were mature.