Brett Wilson and Coronado's Door – John V. Suter

On a treasure hunting expedition with her father, Brett Wilson watches her father enter the fabled golden city of Cibola. The joy of discovery quickly turns to tragedy when the city disappears in front of her eyes.Now in a race against time, Brett must locate the city before her father is lost forever. The only information she has to help her is the tattered old field book of her father and her best friend Natalie’s energy and enthusiasm.

Together with Grandpa Jake and Natalie’s mom Dr. Brown, they must decipher the clues in the field book and understand the earth’s hidden properties to locate Cibola’s final position.