The Charleston quadrangle embraces an area of 938 square miles, extending from latitude 38° on the south to 38°30' to the north, and from longitude 81° 30' on the east to 82° on the west. The quadrangle is located in the State of West Virginia, including parts of the counties of Kanawha, Boone, Putnam, and Lincoln, and is named from the city of Charleston, which is situated at the junction of Elk and Kanawha rivers, in the north-eastern part of the quadrangle.