On the football field, Flathead Valley veterans find a new sense of purpose

For the group of teenage boys assembled on the practice football field by Glacier High School, the world had narrowed to the 100 yards of green grass fenced in by white paint, a bubble so solid that not even the belting lyrics of "The Real Slim Shady" could penetrate it. "Third down! Third down!" a coach shouted. "Trade left! Bunch…