Tyler Armstrong, a 9-year-old boy from South California, has become the youngest person to climb Mount Aconcagua.

The boy wanted to raise awareness for a type of muscular dystrophy that only affects young boys.

Tyler Armstrong reached the summit of Argentina’s 22,837-foot-tall Mount Aconcagua on Christmas Eve, two days ahead of schedule, according to a post on the Top With Tyler Facebook page, which is tracking his progress.

The boy and his father set out December 7 on the arduous journey, which the young climber dedicated to those who can’t walk. He’s raising awareness and money for Duchenne muscular dystrophy, which affects 1 in 3,600 boys.

“It’s when muscles get smaller every time you use them and by 14 they can’t walk,” Tyler Armstrong said of those afflicted with the disease.

Tyler Armstrong has become the youngest person to climb Mount Aconcagua at 9

Temperatures along the route to the top of Mount Aconcagua typically drop to 20 degrees below zero this time of year. And the pinnacle is just below the elevation where oxygen is mandatory.

Tyler Armstrong is the youngest person to scale the towering peak.The previous record had been held by a 10-year-old climbe).

Mount Aconcagua – the highest in both the Western and Southern Hemispheres – is now added to an already impressive list of summits the fourth grader from Yorba Linda has reached.

At the age of 7, Tyler Armstrong climbed 14,505 feet up Mount Whitney, the highest summit in the contiguous US.

Last year, Tyler Armstrong scaled Mount Kilamanjaro, the highest free-standing mountain in the world at 19,341 feet. He had to apply for a special permit for that trek because, at 9, he was a year younger than the age limit.

Tyler Armstrong’s Argentina itinerary planned for him to summit between December 26 and 29. It should take him about three days to climb down from the mountain.

Tyler Armstrong is set to be back in the US on January 5, 2014.

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