Shows portions of Minnesota, Iowa, Wisconsin, and Illinois.; "8-'29"--lower right in neat line; "September 1929 (25M)--lower margin."; Relief shown by shading.; Shows airways, air distances at 10 mile intervals, and stops in red; railroads and cities shown in black.; On verso: schedule, text, and ill. 42 x 48 centimeters, folded to 23 x 11 centimeters Scale approximately 1:1,140,000 General Map Collection