This coverage was obtained in digital form from Chris Barton of the USGS. Bedrock geology in the Hubbard Brook Valley was mapped by C.C. Barton, R.H. Comerlo, and S.W. Bailey, August 1994 to August 1995. The Map is entitled "BEDROCK GEOLOGIC MAP OF HUBBARD BROOK EXPERIMENTAL FOREST AND MAPS OF FRACTURES AND GEOLOGY IN ROADCUTS ALONG INTERSTATE 93, GRAFTON COUNTY, NEW HAMPSHIRE" and was approved for publication on August 28, 1995. The benchmark adjacent to the Hubbard Brook Headquarters building was set by the New Hampshire Department of Transportation in 1993. The station is a standard NHDOT disk stamped "Hubbard Brook 1993", set into the top of a 4 FT long by 5 IN granite monument flush with the ground and level with the parking lot. Located 17.5 FT (5.3 M) southeast from the southeast corner post for a fence and the orange carsonite marker, 49.5 FT (15.1 M) northeast from the north corner of the office building, 60 FT (18.3 M) east from the west face of the concrete curb, 51.0 FT (15.5 M) south from the northeast corner post for a fence. Benchmark location: NAD83 Latitude = 43 56 38.0361 Longitude = 71 42 03.9897 Northing = 160408.164 Meters Easting = 297235.062 Meters NAD27 Latitude = 43 56 37.7891 Longitude = 71 42 05.7012 Northing = 526,241.45 Feet (State Plane Zone 4676) Easting = 490,803.21 Feet Elevation = 833.87 Feet NGVD29 (El order 31). Data distributed as shapefile in Coordinate system EPSG:26919 - NAD83 / UTM zone 19N