Details for Benchmark: HS3977
N 37° 42.083 W 121° 52.750 (NAD 83)
Coordinates may not be exact. Altitude is VERTCON and location is SCALED. (more info)
- In ALAMEDA county, CA View Original Datasheet
- P 24
- Marker Type:
- bench mark disk
- set into the top of a round concrete monument
- May hold, but of type commonly subject to surface motion.
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Documented History (by the NGS)
|01/01/1964 by CGS (MONUMENTED)
|DESCRIBED BY COAST AND GEODETIC SURVEY 1964
4.8 MI NW FROM PLEASANTON. 0.95 MILES NORTHWEST ALONG DIVISION STREET FROM THE WESTERN PACIFIC RAILROAD STATION AT PLEASANTON, THENCE 2.45 MILES NORTHWEST ALONG HOPYARD ROAD, THENCE 1.35 MILES EAST ALONG U.S. HIGHWAY 50, 118 1/2 FEET NORTH OF THE CENTER LINE OF THE NORTH HIGHWAY LANES, 116.3 FEET NORTHWEST OF THE NORTHWEST CORNER OF A CONCRETE BRIDGE, 104 FEET SOUTH-SOUTHWEST OF A POWER LINE POLE WITH 2 GUY WIRES, 108 FEET EAST-SOUTHEAST OF THE EAST CORNER OF A U.S. BORDER PATROL SENTRY POST, ABOUT 1 FOOT LOWER THAN THE HIGHWAY, A DISK ON THE TOP OF A COPPER COATED ROD DRIVEN TO A DEPTH OF 97 FEET. THE UPPER PORTION OF THE ROD IS ENCASED IN A CONCRETE POST FLUSH WITH THE GROUND.
|01/01/1965 by NGS (GOOD)
|RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1965
RECOVERED IN GOOD CONDITION.
- The horizontal coordinates were scaled from a topographic map and have an estimated accuracy of +/- 6 seconds.
- The NAVD 88 height was computed by applying the VERTCON shift value to the NGVD 29 height (displayed under SUPERSEDED SURVEY CONTROL.) The vertical order pertains to the superseded datum.
- The geoid height was determined by GEOID99.