In 1840, and federally financed expedition to explore and document the Pacific Ocean arrived in Honolulu to repair its ships and wait out winter. The leader, Charles Wilkes, decided to climb Mauna Loa to survey it and conduct weather experiments at the summit and to estimate the height of the volcano. After a long and oftentimes trying journey (the climbers needed resupply of water and other items), Wilkes and other expedition members, as well as local hired porters, reached the top in late December and set up this campsite. They remained at the summit for a couple of weeks. Unfortunately, the experiments did not yield any significant results but his estimation of Mauna Loa's height was not far off its actual height. All that remains of the camp are piles of rubble but there is modern shelter. It is possible to reach the site along the Ainapo Trail. The campsite was placed on the National Register of Historic Places in 1974.