Jack's mother is investigating a cougar attack at Mesa Verde, but he cannot explore due to her foster child.

Twelve-year-old Jack and his younger sister visit Mesa Verde National Park, where they delve into the park's history while gradually uncovering the mysterious past of their family's teenage foster child Lucky.

Twelve-year-old Jack, his younger sister, and the family's teenage foster child Troy go to Yellowstone National Park, where Jack's mother, a wildlife veterinarian, is investigating the report that wolves reintroduced to the park have killed a dog there.

Originally published: Washington, D.C.: National Geographic, 2002.

For use in schools and libraries only. The Landon family makes a trip to Death Valley National Park, accompanied by a mysterious new foster child, 14 year-old Leesa Sherman.

When a cougar attacks a hiker in Mesa Verde National Park, the Landons have another mystery on their hands. Jack and Ashley are used to visiting parks with their wildlife veterinarian mother and photographer father, but this time their hands are full with a foster child called Lucky Deal. As Lucky and Jack become friends, Ashley becomes suspicious: What did Lucky take from the burn site? Who did she call in the night? In a midnight showdown at Spruce Tree House, Jack realizes there's more to fear than a killer cat. Cliff-Hanger weaves Native American folklore, natural science, and geography into a heart-pounding thriller. The afterword by Will Morris, Chief of Interpretation and Visitor Services at Mesa Verde, outlines the dangers of cougar attacks and the need to protect wild animals. National Geographic supports K-12 educators with ELA Common Core Resources. Visit www.natgeoed.org/commoncore for more information.

The Landon family travels to Glacier National Park to investigate why grizzly bear cubs are disappearing and become involved with a ten-year-old Mexican runaway boy.