(From the publisher):
Frank and Joe have come to the ruggedly beautiful mountains of Utah to test their wilderness skills. But on their very first day out, after a frayed rope nearly sends Joe plummetting to the bottom of a rocky ravine, they discover that the challenge will be far more perilous than they imagined. This will be a test of survival!
The Hardys have stumbled upon a deadly scheme of greed and sabotage. But to uncover the secret behind it, they'll have to follow the trail of infamous outlaws -- Butch Cassidy and his Hole in the Wall gang. The gang may be long gone, but a new breed of desperado is on the loose...and they're gunning for Frank and Joe!
Original title: Survival of the Fittest
Genre: Fiction→ Crime and Mystery→ Detective Story and Detectives
Fiction→ Children & Young Adult→ Mystery
Fiction→ Children & Young Adult→ Suspense/Thriller