Climb or Die — Edward Myers

After a back-road car accident in the Colorado Rockies seriously injures their parents, athletic fourteen-year-old Danielle and her brainy younger brother, Jake, set out together to find help. Walking twenty miles through deep snow is the most obvious option but seems too risky. The teens decide instead to make a more audacious move: climbing a mountain that Jake believes is nearby and that has a manned weather station at its summit. As they head upward, Danielle and Jake soon realize that they've taken an all-or-nothing gamble: they must climb . . . or die.