" We reached a section where the canyon walls closed in until it was almost claustrophobic. There was little room left on the bank alongside the stream, occasionally forcing us onto rocks that poked through the water. My heels were starting to blister in my ski boots. And to make matters worse, Warren insisted on singing “Ninety-Nine Bottles of Beer on the Wall. "

― Stuart Gibbs , Spy Ski School (Spy School #4)