Cranesville Swamp is located on the West Virginia-Maryland border in Preston County, West Virginia, and Garrett County, Maryland (fig. 1). Its elevation is about 2,500 feet and according to Rumsey (in Shelford, 1926) it covers an area of about 560 acres. On the 7.5 minute series of the U. S. Geological Survey topographic maps it is in the southeastern corner of the Sang Run Quadrangle. As a result of the efforts of The Nature Conservancy, the Cranesville Swamp Nature Sanctuary was established in 1960 by the purchase of about 259 acres. In 1965 this area was proclaimed a Natural History Landmark by the United States Park Service. Robinette (1964) has made a study of the major plant communities of Cranesville Swamp and Mansueti (1958) has given an interesting popular description of the area and some of its biota.