Details for Benchmark: JW1586
N 39° 22.467 W 079° 24.900 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In GARRETT county, MD View Original Datasheet
- D 198
- Marker Type:
- survey disk
- retaining walls, concrete ledge, etc.
- May hold, but of type commonly subject to surface motion.
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Documented History (by the NGS)
|01/01/1991 by MDSHA (MONUMENTED)
|DESCRIBED BY MARYLAND DOT HIGHWAY ADMINISTRATION 1991
THE MARK IS LOCATED ABOUT 1.5 MI (2.4 KM) NORTH-NORTHEAST OF GORTNER, 2.45 MI (3.94 KM) SOUTH-SOUTHWEST OF OAKLAND AND ALONG U.S. HIGHWAY 219. IT IS ON ROAD RIGHT-OF-WAY. TO REACH THE MARK FROM THE POST OFFICE IN OAKLAND, GO SOUTHWEST ON SECOND STREET FOR 0.2 MI (0.3 KM) TO U.S. HIGHWAY 219. TURN LEFT AND GO SOUTH ON U.S. HIGHWAY 219 FOR 2.9 MI (4.7 KM) TO THE MARK ON THE RIGHT. THE POINT IS MARKED WITH A MARYLAND STATE HIGHWAY ADMINISTRATION SURVEY DISK SET IN THE NORTHEAST CORNER OF THE TOP OF A CONCRETE HEADWALL. IT IS 68.0 FT (20.7 M) NORTHWEST OF THE CENTER OF U.S. HIGHWAY 219, 32.5 FT (9.9 M) SOUTHWEST OF A TELEPHONE POLE NUMBERED C AND P 86 AND 1.5 FT (0.5 M) NORTHWEST OF THE WITNESS POST. IT IS ABOUT 11.0 FT (3.4 M) BELOW THE SURFACE OF THE ROAD.
- 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.