"Piper Sullivan was in a strange hiking accident last month and has been in a coma ever since. Her older sister, Savannah, can't pretend to be optimistic about it--things look bad. Piper will likely never wake up, and Savannah will never get any answers about what exactly happened. But then Savannah finds a note in Piper's locker inviting Piper to a meeting of their school's wilderness club...at the very place and on the very day she fell. Which means...

When rebellious seventeen-year-old Rilla is sent from West Virginia to stay with her park ranger sister in Yosemite National Park, she risks everything as her summer becomes one ecstatic, harrowing experience after another.