Last September, Kristen Kelliher climbed Mount Mansfield. In doing so, she set a record. She became the youngest woman to summit the highest points in each of the 48 continental United States. That day, Kelliher was 17 years, 4 months and 3 days old.

 

Now, she has her sights set on another big goal: summiting the highpoints in all 50 states. All that's left: climbing Hawaii's Mauna Kea and, most daunting of all, Alaska's Mt. McKinley, also known as Denali. At 20,320 feet, McKinley is the highest mountain in North America.