This is volume 11 in Mysteries in Our National Parks .

This book has been graded for interest at 9-12 years.

This book was published 2002 by Turtleback Books .

Gloria Skurzynski has written more than 30 children's books. Her nonfiction book, Almost the Real Thing, won the American Institute of Physics Science Writing Award. She has written several nonfiction books for National Geographic including Are We Alone, an NSTA Outstanding Science Trade Book for Young People and an IRA/CBC Young Adults' Choice for 2006. She lives in Boise, ID. Visit Gloria Skurzynski at her Web site: www. gloriabooks. com.