Independence Rock

Independence Rock is a large granite monolith in southwestern Natrona County, Wyoming, about 60 miles southwest of Casper, standing approximately 130 feet high, 1,900 feet long and 850 feet wide beside the Sweetwater River at the southeast end of the Granite Mountains. The rock is composed of Archean granite typical of the surrounding region, its rounded form resembling other granite inselbergs such as Enchanted Rock in Texas, though smaller. It became a famous waypoint on the Oregon, Mormon and California trails in the nineteenth century, when emigrants aimed to reach it by the Fourth of July to ensure safe passage over the mountains before winter snow; thousands carved their names into its surface, leading the missionary Pierre-Jean De Smet to call it the Register of the Desert in 1840. It was designated a National Historic Landmark in 1961 and is now Wyoming's Independence Rock State Historic Site.