Printed on back, top left corner: "Climax Colorado is and industrial enterprise of giant size. It has the largest underground mining operation in north America, the second largest in the world. Bartlett Mountain, 13,863 feet, is a source of molybdenum, containing 85% of the known world's supply. Fremont Pass, 11,320 feet, was the western boundary of the Louisiana Purchase of 1803., Printing Number: P33911; D30