Reporting from Camp Hale, Colo. - As soon as Renee Legro saw the sheep, she screamed. The herd, 1,300 strong, has been coming for 30 years to graze in this valley on the backside of the Continental Divide. But as Colorado has become an adventure sports destination, the once-empty valley has filled with hikers, campers and mountain bikers like Legro, and she was about to tragically embody the collision of the old West with the new. Legro, 33, screamed because she knew what came with the herd -- guard dogs. Shortly after she rolled down a hill and came upon...