Norris Geyser Basin Museum, Yellowstone National Park

"Do you want your own map?" Penelope Vaughn knelt down, smiling at the little girl in front of her. "It'll show you how to get everywhere you're going to visit today. Maybe you can help be the navigator for your dad."

The girl nodded shyly, her pigtails bobbing as she reached out. She hadn't said a word since her family approached Penny, but her eyes were sparkling with excitement as her chubby fingers closed ...