An 18-year-old woman has reached the summit of Mount Everest, becoming what is believed to be the youngest person to scale the highest peaks on each of the seven continents.

"We made it to the top!" Samantha Larson, of Long Beach, Calif., gasped to her mother in New York via satellite phone from the top of Everest on Thursday, the Los Angeles Times reported Saturday.

According to 7summits.com, a Web site that tracks those who have accomplished the feat, completing the climb in Nepal makes Larson the youngest person to have completed the "seven summits" challenge, breaking a 2006 record set by then-20-year-old British climber Rhys Miles Jones.

Larson graduated from high school in 2006, and put off attending Stanford University for a year so she could scale some of the world's tallest peaks with her father.

The Nepalese government said Friday she was the youngest foreigner ever to reach the 29,035-foot (8,850-meter) summit of Everest, though some climbing Web sites claim a 17-year-old boy from France did it in 1990.

A 15-year-old Sherpa girl from Nepal was the youngest ever to climb Everest.

Larson, who has been climbing since she was a child, reached the summit of South America's Aconcagua when she was 13 and Africa's Mount Kilimanjaro when she was 14.

She has "a kind of stamina and persistence that just seems to be part of her nature, and it has been since she was little," said Larson's mother, Sarah Hanson, according to the Los Angeles Times.

Hanson said her daughter was only halfway down the mountain when she heard from her Friday.

Larson and her father, 51-year-old anesthesiologist David Larson, planned to reach base camp on Friday and Nepal's capital, Katmandu, on Monday, then return to Southern California on Wednesday.

Since New Zealander Edmund Hillary and Sherpa Tenzing Norgay first conquered Everest on May 29, 1953, about 2,000 climbers have scaled the mountain.