Skurzynski, Gloria

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.

While their parents study why wolverines are disappearing from Alaska's Denali National Park, Jack and Ashley are stranded in a remote area with their mysterious new foster brother when a hit man's bullet triggers an avalanche.

When he is suddenly stricken by the rare halving disease, Gustavus meets progressively smaller animals, from dogs to aphids, in his search for help.

A novel of the Pied Piper legend told from the standpoint of a 14-year-old baker's assistant who dreams of freedom from his harsh medieval life and of a new life with the piper.

Having won the Virtual War for the Western Hemisphere Foundation, fifteen-year-old Corgan finds himself raising a clone of the young mutant genius who helped him win before dying.

While lost in a tunnel at Carlsbad Cavern, thirteen-year-old Jack, eleven-year-old Ashley, and their eight-year-old foster brother, Sam, think bats and darkness are their worst problems, until they stumble across thieves.

What s causing the deaths of desert bighorn sheep in Death Valley National Park? Wildlife veterinarian Olivia Landon has been called in to investigate. The plot thickens when her daughter, Ashley, is kidnapped by militants who mistake her for Leesa, a mysterious girl temporarily in the Landons care. Tension builds to a spine-chilling climax when a showdown in the desert leads the family to a missile testing site and the key to what is killing the sheep.

The Three Peaks Elementary Science Club uses science to explain the mystery of vanishing creatures.

The Three Peaks Elementary Science Club uses science to explain the mystery of a haunted silver mine.

A mystery about beached whales at Acadia National Park.