The range of variation in epiphyseal fusion in North American populations has not been sufficiently established. This significant oversight can lead to exclusion of persons of interest in a forensic investigation. This study evaluates epiphyseal fusion of the distal tibia and fibula in 570 European-, African-, and Mexican-American children and young adults. Radiographs of 270 females aged 9 to 17 and 300 males aged 11 to 20 were analyzed to assess the range of variation of epiphyseal fusion at each age. Results indicate that complete fusion in females occurs as early as 12 years in the distal tibia and fibula. All females demonstrated complete fusion by 16 years with no significant differences between ancestral groups. Complete fusion in males occurs as early as 14 years in both epiphyses. All males demonstrated complete fusion by 19 years. Significant differences in the earliest age of complete fusion showed that African- and Mexican-American males demonstrate complete fusion as early as 14 years in both epiphyses while European-American males do not express complete fusion until 16 years.