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 Grace State Forest Mount Grace State Forest Mount Grace State Forest is a publicly owned forest with recreational features located in the town of Warwick. The state forest centers around Mount Grace, which at is the third highest point in Massachusetts east of the Connecticut River after Mount Wachusett and Mount Watatic. It is bordered by portions of Warwick State Forest to the east and west and is managed by the Massachusetts Department of Conservation and Recreation. Mount Grace is said to be named after the baby daughter of Mary Rowlandson, a woman captured by Wompanoag warriors during King Philip's War, who according