By the start of World War II the U.S. Army had become more mechanized, horses had lost their ranking as a mode of transportation, but the mule continued to be of great value - - because of the superior ability to negotiate areas inaccessible to tanks and other vehicles, such as the mountains of Italy and the jungles of Burma. Mobilization actually began in 1930, with an authorization for 3,500 mules. By 1944 and 1945, some 14,000 mules were used by the 10th Mountain Division in northern Italy.