The Last Season by Eric Blehm
Though an outdoor adventure biography, this book reads very much like a mystery. When veteran emergency rescue ranger Randy Morgensen goes missing himself in Yosemite, no one knows what to think. Blehm's suspenseful writing shows how his fellow rangers, civilian search teams, and park personnel try to piece together the puzzle of his disappearance. A great summer read! Recommended by Kelly.
Destined to become a classic of adventure literature, The Last Season examines the extraordinary life of legendary backcountry ranger Randy Morgenson and his mysterious disappearance in California's unforgiving Sierra Nevada—mountains as perilous as they are beautiful.