Natural-color and color-infrared aerial photography at scales of 1:30 000, 1:50 000, and 1:70 000 were evaluated for the interpretation of forest-stand density, height, and species class, for test areas in the boreal and foothills regions of Alberta. Accuracy was assessed by comparing photo interpreter identification to field measurements. When averaged over all scales, color film types did not differ in accuracy. Scale affected identification accuracy for density and species class. The 1:70 000 scale was most accurate for estimating density and least accurate for species class. Scale did not affect identification accuracy for 6-m height classes. Interpreter inventory experience and color-discrimination ability both affected accuracy for species class, but not density or height. Standard 1:15 000 scale black and white photography was not significantly more accurate than any of the other film–scale combinations for identification of density, height, or species class.