Around noon on Sunday, March 31, Alicia Judy, 40, left her home in Scottsdale to run 16 to 18 miles on the Spur Cross Trail, which would lead her to Skull Mesa, a breathtaking summit surrounded by towering cactus trees. The path was very familiar to Judy, an experienced trail runner and nurse who has been running through the parks in her area regularly since moving to Arizona five years ago. Still, she studied the map before she left, double-checked her route with a fellow hiker on the trailhead, and made sure to pack her phone, compass, water, and maps...