Americans developed specialized mountain and winter troops after the Soviet invasion of Finland in 1939 highlighted the military value of ski-trained soldiers. The American Alpine Club and National Ski Patrol pressed for mountain warfare training, and the War Department formed ski patrol units in 1940 before activating the 1st Battalion, 87th Mountain Infantry Regiment at Fort Lewis in 1941. Recruited in part through the National Ski Patrol, the force expanded with additional battalions, moved to Camp Hale in Colorado for training, and in 1943 became the 10th Light Division (Alpine), later renamed the 10th Mountain Division. After service on Kiska in the Aleutians, where the enemy had already withdrawn but losses still occurred, the division went to Italy, entering combat in January 1945. Under General George P. Hays, it carried out a difficult mountain campaign that included the night assault on Riva Ridge, the capture of Mount Belvedere and nearby heights, continued attacks toward the northeast, and heavy fighting during the spring offensive. The division then broke out of the Apennines into the Po Valley, crossed the Po River under fire, advanced through northern Italy, and reached places including Verona, Lake Garda, Torbole, and Riva before the German surrender in Italy on May 2, 1945. Afterward it moved to northeastern Italy, returned to the U.S. as plans turned toward Japan, and was inactivated on November 30, 1945. The division's service in Italy involved 19,912 men, with 977 killed in action there, 19 killed on Kiska, 3,938 wounded, 28 prisoners of war, and numerous decorations, including one Congressional Medal of Honor.