Details for Benchmark: JW1752
N 39° 39.817 W 079° 28.750 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In PRESTON county, WV View Original Datasheet
- SHA 252
- Marker Type:
- survey disk
- in rock outcrop
- Most reliable and expected to hold position/elevation well.
Benchmarks may be on private property or in dangerous locations. Obey local laws. By using the services on Geocaching.com you agree to this disclaimer.
Documented History (by the NGS)
|01/01/1992 by MDSHA (MONUMENTED)
|DESCRIBED BY MARYLAND DOT HIGHWAY ADMINISTRATION 1992
THE MARKER IS LOCATED ABOUT 3.9 MI (6.3 KM) WEST OF FRIENDSVILLE, 8.8 MI (14.2 KM) WEST-NORTHWEST OF ACCIDENT, AND 0.1 MI (0.2 KM) WEST OF THE MARYLAND-WEST VIRGINIA STATE LINE. IT IS LOCATED ON THE INTERSTATE HIGHWAY 68 RIGHT-OF-WAY. TO REACH FROM A POINT WHERE INTERSTATE HIGHWAY 68 CROSSES THE MARYLAND-WEST VIRGINIA STATE LINE, GO WEST ON INTERSTATE HIGHWAY 68 FOR 0.15 MI (0.24 KM) TO THE MARKER ON THE RIGHT ALONG THE NORTH SIDE OF THE WESTBOUND LANE OF INTERSTATE HIGHWAY 68. THE POINT IS MARKED WITH A MARYLAND STATE HIGHWAY ADMINISTRATION SURVEY DISK, CEMENTED IN A DRILL HOLE IN AN OUTCROP OF BEDROCK. IT IS 78.0 FT (23.8 M) NORTH OF THE CENTER OF THE WESTBOUND LANE OF INTERSTATE HIGHWAY 68, 8.0 FT (2.4 M) NORTH OF A CARSONITE WITNESS POST, 41.0 FT (12.5 M) NORTH OF THE CENTER OF A DRAINAGE DITCH, AND 50.0 FT (15.2 M) SOUTH OF THE SOUTH FACE OF A HIGH ROCK HIGHWAY CUT. IT IS ABOUT 6.0 FT (1.8 M) HIGHER THAN THE SURFACE OF INTERSTATE HIGHWAY 68.
|08/17/1993 by NGS (GOOD)
|RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1993
6.4 KM (3.95 MI) WESTERLY ALONG INTERSTATE HIGHWAY 68 FROM THE JUNCTION OF STATE HIGHWAY 42 IN FRIENDSVILLE, MARYLAND (EXIT 4), NEAR THE CENTER OF A 4 BY 5-FOOT EXPOSED AREA OF BEDROCK IN A HIGHWAY CUT, 23.5 M (77.1 FT) NORTH OF THE CENTER OF THE WESTBOUND LANES OF THE HIGHWAY, 15.3 M (50.2 FT) SOUTH OF THE SOUTH FACE OF A ROCK WALL, 2.5 M (8.2 FT) NORTH OF A WITNESS POST, AND 0.8 M (2.6 FT) ABOVE THE LEVEL OF THE HIGHWAY.
- The horizontal coordinates were scaled from a topographic map and have an estimated accuracy of +/- 6 seconds.
- The orthometric height was determined by differential leveling and adjusted by the National Geodetic Survey in April 1995.
- The geoid height was determined by GEOID99.
- The dynamic height is computed by dividing the NAVD 88 geopotential number by the normal gravity value computed on the Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45 degrees latitude (g = 980.6199 gals.).
- The modeled gravity was interpolated from observed gravity values.