A couple of decades before the words "global warming" hit the headlines, a loner named Billy Barr moved into the Colorado wilderness. He lived by himself at nearly 10,000 feet , miles from the nearest town. So to pass the time, he kept meticulous notes about the weather and animals. For scientists studying climate change, Billy's notebooks turn out to be heaven sent -- without this kind of data, it's tricky figuring out the way things used to be. And now there's a full-speed search on to find more people like him. From Gothic, Colorado, Zachary Barr -- no relation to Billy, by the way -- has the story.