Skis carried Mason Flagg, 85, of Worcester to war, although he says the famed 10th Mountain Division troopers never actually fought on skis, and training at Camp Hale in the Colorado Rockies was almost as tough as the combat itself. Sixteen thousand served and 1,600 remain now, 62 years after World War II ended. The last national reunion that will ever be organized by veterans of the 10th was held in Leadville, Colo., recently. Future ceremonies may happen, but they will be arranged by descendants of the WWII mountain troops. The troopers are now all in their 80s and 90s. Mason began skiing at Wachusett before ski tows, but says he prefers the high-speed quads, snowmaking, and grooming of today.