Chinook salmon introduced into Lake Superior were sampled in Cherry Creek in 1971, in the Dead River during 1974 and 1975, and in Presque Isle Harbor during 1974 and 1975. A total of 80 males and 30 females were sampled. Analysis of the scales revealed that maturation could occur at ages I+, II+, III+, and IV+. All fish were found to have a planting check present; no fish were found having more than four annuli. There were no essential differences in age and growth between the sexes.