Madison Boulder

Madison Boulder Natural Area
The Madison Boulder as photographed in 1922
Madison Boulder is located in New Hampshire
Madison Boulder
Madison Boulder
Location in New Hampshire
LocationMadison, New Hampshire, United States
Coordinates43°55′53″N 71°10′04″W / 43.93146°N 71.1678°W / 43.93146; -71.1678[1]
Area17 acres (6.9 ha)[2]
Elevation512 feet (156 m)[1]
Established1946[3]
Administered byNew Hampshire Division of Parks and Recreation
DesignationNational Natural Landmark
WebsiteMadison Boulder Natural Area

The Madison Boulder is one of the largest known glacial erratics in North America and among the largest in the world; it is preserved in the 17-acre (6.9 ha) Madison Boulder Natural Area in Madison, New Hampshire.[4] The boulder is a huge granite rock measuring 83 feet (25 m) in length, 23 feet (7.0 m) in height above the ground, and 37 feet (11 m) in width. It weighs upwards of 5,000 short tons (4,500,000 kg). A part of the block is buried, probably to a depth of 10 to 12 feet (3.0 to 3.7 m).[4] It was acquired by the state from the Kennett family in 1946.[3] In 1970, Madison Boulder was designated as a National Natural Landmark by the National Park Service.[5]

  1. ^ a b "Madison Boulder State Geologic Site". Geographic Names Information System. United States Geological Survey, United States Department of the Interior.
  2. ^ Cite error: The named reference nhdred was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference study was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference nhsp was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference nnl was invoked but never defined (see the help page).