Elephant Rocks State Park

Elephant Rocks State Park is a state-owned geologic reserve and public recreation area encompassing an outcropping of Precambrian granite in the Saint Francois Mountains in the U.S. state of Missouri. The state park is named for a string of large granite boulders which resemble a train of pink circus elephants. The park was created following the donation of the land to the state in 1967 by geologist John Stafford. The park is used for picnicking, rock climbing, and trail exploration. It is managed by the Missouri Department of Natural Resources.GeologyGeologically, Elephant Rocks State Park consists of a pile of residual boulders of weathered Graniteville Granite. It is a medium- to coarse-grained, muscovite-biotite alkali granite that, on the average, consists of 55 percent alkali feldspar, 40 percent quartz, and less than 5 percent mafic minerals. The Graniteville Granite was formed in the Proterozoic 1.5 billion years ago from a dome of molten magma. Nearly vertical fractures formed in the stone as it cooled, and uplift of the formation enhanced the fracturing. Eventually the overlying strata were removed through erosion, exposing the granite dome. With exposure, water and ice worked to weather and erode the surface of the granite along fracture joints. Spheroidal weathering of the granite and later erosion of the resulting saprolite that once surrounded these corestones left the elephant rocks as boulders perched on the ground surface.