YA Geocaching themed Novels

While compiling a list of geocaching themed mystery novels, I came across several YA novels also with a geocaching theme.  

Code by Kathy Reichs
Tory and the rest of the Virals are put to the ultimate test when they find a geocache containing an ornate puzzle box. Shelton decodes the cipher inside, only to find more tantalizing clues left by "The Gamemaster." A second, greater geocache is within reach—if the Virals are up to the challenge. But the hunt takes a dark turn when Tory locates the other box—it contains a fake bomb, along with a sinister proposal from The Gamemaster. Now, the real game has begun: another bomb is out there—a real one—and the clock is ticking.

The Birthday Cache by Amanda Zieba
"While twelve year old Mason Miles and his parents love their nomadic lifestyle living and working across the nation in their RV, his twin sister Molly is craving a normal life and scheming to put an stop to their endless road trip. For their twelfth birthday the twins open a GPS receiver and fall in love with the sport of geocaching. When they stumble upon a mysterious puzzle cache will their travels become interesting enough to change Molly's mind?"

Decrypting The Cache by Jennifer Kirsch
Two "young adult adventure" books, with a geocaching theme,  have been written by Jennifer Kirsh, Decrypting The Cache & The Limiteds

Description of Book One, from Amazon
Thirteen-year-old Erin jumps at any chance to go geocaching — using GPS technology to locate hidden caches. But family outings seem as likely as finding a cache in an active volcano after Erin’s unemployed dad relocates to another state. When her parents then stop talking to each other and they lose their house, Erin feels about as secure as a fault line during an earthquake. Setting out with her friend Dev, Erin discovers a mysterious note inside a geocache. Convinced it leads to valuables that could help her family, she and Dev track down geocaching clues. Besides cryptic messages, they face secret tunnel networks, gobs of chewed bubblegum, and woods bristling with vengeful wasps. Chess team bullies, scheming geocachers, and self-doubt also threaten their mission. Meanwhile, Erin’s dad extends his remote stay, and financial worries take up permanent residence at home. Will Erin and Dev unravel the mystery before her family falls apart?

Hide & Seek by Katy Grant
When a teenage boy on a high-tech treasure hunt inadvertently stumbles into the middle of a crime, he finds himself in a dangerous situation that could turn deadly.

After a summer cooped up in his family's store selling bait, tackle, and soft drinks to tourists, fourteen-year-old Chase finally gets a chance to go on his first solo geocaching adventure.

Using his GPS, he uncovers the geocache-a small metal box-hidden deep in the woods in some undergrowth. Inside, with a few plastic army men and a log book, is a troubling message for help in a child's handwriting.

When Chase returns later, he finds another message in the geocache box, this time asking for food. He is curious -and worried-about the mysterious individuals leaving the messages. What if they are hopelessly lost or hiding from something-or someone?

Before he can turn to the adults around him for help, Chase is pulled into a complex, dangerous drama and a chilling confrontation with an unstable father who will stop at nothing to hold on to his children.
A YA geocaching novel from the author of Cache A Predator

Eclair Goes Geocaching by M. Weidenbenner

When seven-year-old Éclair goes geocaching for the first time, she finds a treasure that isn't the one she imagined. 

Young readers will discover what geocaching is all about through Éclair's journey with her eccentric grandma.

A boxcar Children book, with a geocaching theme!
The Box That Watch Found