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 Mansfield State Forest is listed as a National Natural Landmark. Vermont Route 108 between Stowe Mountain Resort and Smugglers' Notch Resort is a federally designated Scenic By-way. Mount Mansfield State Forest Mount Mansfield State Forest covers in seven towns in Chittenden, Lamoille and Washington counties in Vermont. The towns are Bolton and Underhill in Chittenden County, Cambridge, Johnson, Morristown and Stowe in Lamoille County, and Waterbury in Washington County. Mt. Mansfield State Forest is the largest contiguous landholding owned by the Vermont Department of Forests, Parks and Recreation. There are four state parks located in the forest: Little River State Park, Smugglers' Notch