Fisher began her bid at completing the Seven Summits challenge in January 2003, with Aconcagua in Argentina, followed in July by Mount Kilimanjaro in Tanzania and Mount Elbrus in Russia. In 2004, she climbed Mount Kosciuszko in Australia in January, and Mount McKinley in May. She climbed her penultimate peak of the Seven Summits, Vinson Massif in Antarctica, in January 2005. In June 2005, Fisher successfully reached the summit of Mount Everest in Nepal, making her at 20 years old the youngest American to have done so at the time. Her ascent of Everest marked her completion of the Seven Summits; she became the youngest person ever to have completed the challenge. Most of Fisher's Seven Summit climbs were made with expeditions run by Alpine Ascents International, a Seattle-based guiding company, costing a total of US$96,000.