Lost Cipher — Michael Oechsle

In this tale of loss, friendship, adventure, and survival, Lucas and his fellow campers must find a treasure -- and strength in one another.

Lucas's father has recently died in Afghanistan, and, to help him cope, his grandmother sends him to Camp Kawani, a camp for kids who have lost a parent. While there, he hears about the local legend of Thomas Jefferson Beale. Beale supposedly hid a hoard of gold in the mountains two hundred years before. The location is encrypted in a set of codes no one has ever been able to decipher. When Lucas and his newfound friends decide to track down the treasure, they embark on a mission that could be too dangerous to survive.
 
Part heart-rending story of grief, part compelling adventure, this story shows how friends are there to help navigate hardship -- and treasure hunts.