Details for Benchmark: HL0646
N 37° 47.977 W 107° 40.446 (NAD 83)
Coordinates may not be exact. Altitude is GPS OBS and location is ADJUSTED. (more info)
- In SAN JUAN county, CO View Original Datasheet
- V T
- Marker Type:
- horizontal control disk
- in rock outcrop
- Most reliable and expected to hold position/elevation well.
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Documented History (by the NGS)
|01/01/1952 by USGS (MONUMENTED)
|DESCRIBED BY US GEOLOGICAL SURVEY 1952
STATION IS LOCATED ABOUT 1.0 MI. SSW. OF SILVERTON, COLORADO, AND 205 FT. E. OF HIGHWAY, ON THE HIGHEST POINT OF A SMALL KNOLL.
TO REACH FROM THE POST OFFICE AT SILVERTON, DRIVE S. ALONG HIGHWAY 550 FOR 1.9 MI. TO WIDE GRADUAL CURVE AND STATION SITE.
STATION MARK--STANDARD TABLET, STAMPED ---V.T. 1952 VABM 9598---, CEMENTED IN GRANITE OUTCROP.
|01/01/1952 by USGS (GOOD)
|RECOVERY NOTE BY US GEOLOGICAL SURVEY 1952
RECOVERED IN GOOD CONDITION.
|06/28/1991 by NGS (GOOD)
|RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1991
STATION IS LOCATED ABOUT 1.5 KM (0.9 MI) SOUTHWEST OF SILVERTON, IN THE SAN JUAN NATIONAL FOREST, 1 KM (0.6 MI) SOUTHEAST OF A HAIRPIN HIGHWAY CURVE, JUST OFF US HIGHWAY 550, IN THE MIDDLE OF A SLOPING NORTHWEST-SOUTHEAST RIDGE THAT PARALLELS THE HIGHWAY AND IS ON THE EAST SLOPE OF SULTAN MOUNTAIN. OWNERSHIP--US FOREST SERVICE. TO REACH FROM THE JUNCTION OF US HIGHWAY 550 AND STATE HIGHWAY 110 AT THE SOUTHWEST END OF A LARGE TRAFFIC TRIANGLE JUST SOUTHWEST OF SILVERTON, GO SOUTHWEST ON HIGHWAY 550 FOR 0.75 MI (1.21 KM) TO A TRACK ROAD AND GATE ON THE RIGHT JUST PAST A HAIRPIN CURVE. CONTINUE UPGRADE FOR 0.35 MI (0.56 KM) TO A NARROW TURNOUT ON THE LEFT OPPOSITE A BROKEN ROCK FACE AND THE END OF TRUCK TRAVEL. CONTINUE UPHILL FOR 0.9 MI (1.4 KM) TO A TURNOUT ON THE LEFT AND ENOUGH ROOM TO TURN AROUND. PACK DOWN INTO RAVINE, THEN RIGHT, SOUTHEAST, FOR 150 FT (45.7 M) , THEN LEFT, EASTERLY, UP SIDE OF RIDGE FOR 150 FT (45.7 M) TO STATION. NOTE--300 FT PACK TO STATION. STATION MARK PROJECTS 5 MM FROM A DRILL HOLE IN A 1 M (3.3 FT) X 2.6 M (8.5 FT) X 0.1 M (0.3 FT) HIGH ROCK OUTCROP ABOUT 60 M (196.8 FT) NORTHWEST OF HIGH GROUND. IT IS ABOUT 100 M (328.1 FT) NORTHEAST OF, AND 5 M (16.4 FT) HIGHER THAN THE HIGHWAY, 150 M (492.1 FT) EAST OF THE TURNOUT, 0.9 M (3.0 FT) WEST OF A FIBERGLASS WITNESS POST, 7.8 M (25.6 FT) WEST-SOUTHWEST OF A 40-CM SPRUCE TREE, 6.0 M (19.7 FT) NORTHWEST OF THE NORTHWEST AND HIGHEST END OF A 1 M (3.3 FT) X 1 M (3.3 FT) X 0.5 M (1.6 FT) HIGH BOULDER SITTING ON TOP OF THE GROUND. DESCRIBED BY G.R.HEID
|07/08/1993 by NGS (GOOD)
|RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1993 (RSC)
RECOVERED AS DESCRIBED.
|07/15/1998 by CODOT (GOOD)
|RECOVERY NOTE BY COLORADO DEPARTMENT OF TRANSPORTATION 1998 (RSC)
RECOVERED AS DESCRIBED.
- The horizontal coordinates were established by GPS observations and adjusted by the National Geodetic Survey in May 1992.
- The orthometric height was determined by GPS observations and a high-resolution geoid model.
- The X, Y, and Z were computed from the position and the ellipsoidal ht.
- The Laplace correction was computed from DEFLEC99 derived deflections.
- The ellipsoidal height was determined by GPS observations and is referenced to NAD 83.
- The geoid height was determined by GEOID99.