Mount Rushmore community. Recent pine beetle infestations have threatened the forest. Mount Rushmore is largely composed of granite. The memorial is carved on the northwest margin of the Black Elk Peak granite batholith in the Black Hills of South Dakota, so the geologic formations of the heart of the Black Hills region are also evident at Mount Rushmore. The batholith magma intruded into the pre-existing mica schist rocks during the Proterozoic, 1.6 billion years ago. Coarse grained pegmatite dikes are associated with the granite intrusion of Black Elk Peak and are visibly lighter in color, thus explaining the light-colored streaks on the
Mount San Jacinto State Park the park temporarily over certain days. Mount San Jacinto State Park Mount San Jacinto State Park is in the San Jacinto Mountains, of the Peninsular Ranges system, in Riverside County, California, United States. A majority of the park is within the Santa Rosa and San Jacinto Mountains National Monument. The park is near the Greater Los Angeles and the San Diego metropolitan area. The Mount San Jacinto State Park encompasses the weathered granite summit of Mount San Jacinto, which at above sea level makes this the second highest peak and mountain range in Southern California. It is accessible by the