for walt and penny copeland, the small town of hayden, colorado has been home for 5 decades.h in the rocky mountains, they're that much closer to the deep blue skies and puffy white clouds. >> maybe take a bunch of deep breaths. >> don't cheat on your oxygen test. >> i didn't. [laughter] john: three years ago, they were comfortably settled into retired life when walt began having breathing problems. >> i was having a checkup after my heart valve. once a year, i'd go for a checkup. they found a little spot on my left lung that was kind of cloudy. john: he was diagnosed with pneumonitis -- inflammation of the lung tissue, also call farmers lung. >> there's hundreds of different types of farmer's lung, which are mold, sawdust, you know, all kinds of stuff. i grew up with parents who smoked and i worked out at the coal mine and i hauled fuel and stuff like that, but no scarring, nothing showed up. john: retired from long-haul trucking, walt thought he was done with long, regularly scheduled drives. but from his home in hayden, going to a pulmonologist every three months for check