Johnson, Aaron, 1976- National park mystery series #5

Before Jake's grandfather died, he was on the trail of a centuries-old mystery. He has entrusted that mystery to Jake, leaving behind a set of hidden codes, riddles, maps, and other clues that lead Jake and his friends on a scavenger hunt while camping in the most rugged wilderness of the national parks. The mystery unfolds as Jake, Amber, and Wes learn about survival skills, natural history, integrity, character, and friendship. Along the way, they discover they are not the only ones on this quest. An elusive shadow group is close on their heels. --