 While neither the earthquake of 1868 nor that of 1975 caused a measurable change in the Great Crack, lava welled out of the lower of the Great Crack in 1823.Visitors can find trails, rock walls, and archaeological sites from as old as the 12th century around the Great Crack.Approximately of private land were purchased during the presidency of Bill Clinton, specifically to protect various artifacts in this area, as well as the habitat of local wildlife.