Details for Benchmark: HL0277
N 37° 52.433 W 107° 43.583 (NAD 83)
Coordinates may not be exact. Altitude is POSTED and location is SCALED. (more info)
- In SAN JUAN county, CO View Original Datasheet
- H 23
- Marker Type:
- survey disk
- in a boulder
- May hold, but of type commonly subject to surface motion.
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Documented History (by the NGS)
|01/01/1927 by USGS (MONUMENTED)
|01/01/1928 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1928
7.4 MI NW FROM SILVERTON. 40 FT. EAST BY 150 FT. NORTH OF A RIGHT ANGLE TURN IN HIGHWAY, AT MILL CREEK, IN TOP OF A LARGE BOULDER. BOULDER MARKED U.S. 10277.2 P.B.M.
|01/01/1985 by NGS (MARK NOT FOUND)
|RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1985
MARK NOT FOUND.
|07/05/1991 by USPSQD (GOOD)
|RECOVERY NOTE BY US POWER SQUADRON 1991 (WLR)
RECOVERED IN GOOD CONDITION.
- 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 1992. * This is a POSTED BENCH MARK height. Code A indicates a distribution rate of 0.0 thru 1.0 mm/km.
- 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.