NV0860 "L422 - 1983"
Located in the Twin Falls, Jerome County, Idaho, this NGS mark lies adjacent to State Route 93 on the northwest abutment for the Perrine Memorial Bridge over the Snake River. Found NGS mark stamped "L422 1983" at 17:15, 22 July 2019 as described and in good condition. Set in the sidewalk, this mark is easily located. Go to description is adequate to find the mark.
Published NAD83 coordinates are located about 126 feet southwesterly of the found WGS84 coordinates. WGS84 coordinates for the mark found by 4 minute occupation with 10 strong satellites and 1 WAAS satellite.
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Found Details for Benchmark: NV0860
N 42° 36.153 W 114° 27.193 (WGS 84)
Altitude: 3610
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Published Details for Benchmark: NV0860
N 42° 36.133 W 114° 27.200 (NAD 83)
Altitude: 3617.38
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
Location: In Jerome County, ID
Designation: L 422
Marker Type: bench mark disk
Setting: abutments and piers of large bridges
Stability: Most reliable and expected to hold position/elevation well.
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Documented History (by the NGS)
01/01/1983 by NGS (MONUMENTED) DESCRIBED BY NATIONAL GEODETIC SURVEY 1983 4.7 KM (2.9 MI) NORTH FROM TWIN FALLS. 4.7 KM (2.95 MI) NORTH ALONG U.S. HIGHWAY 93 FROM THE JUNCTION OF STATE HIGHWAY 74 AT TWIN FALLS, IN TOP OF AND 0.3 METER (1 FT) EAST OF THE WEST END OF THE NORTH ABUTMENT FOR THE STEEL ARCH BRIDGE OVER THE SNAKE RIVER, 6.7 METERS (22 FT) WEST OF THE CENTERLINE OF THE SOUTH BOUND LANES AND 4.9 METERS (16 FT) SOUTH OF THE NORTH END OF A METAL GUARDRAIL. THE MARK IS ABOVE LEVEL WITH THE SIDEWALK.
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| NV0860 "L422 - 1983" - Benchmark detail. |
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| NV0860 "L422 - 1983" - Benchmark and GPSr. |
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| NV0860 "L422 - 1983" - Benchmark setting in the abutment of the Perrine Bridge and U.S. Highway 93 over the Snake River. View southerly. |
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| NV0860 "L422 - 1983" - Benchmark setting in the abutment of the Perrine Bridge and U.S. Highway 93 over the Snake River. View southwesterly. |
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| NV0860 "L422 - 1983" - Benchmark setting in the abutment of the Perrine Bridge and U.S. Highway 93 over the Snake River. View northerly. |
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| NV0860 "L422 - 1983" - Benchmark setting. The northerly abutment of the Perrine Bridge and U.S. Highway 93 over the Snake River. View easterly. |
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| NV0860 "L422 - 1983" - The Perrine Bridge and U.S. Highway 93 over the Snake River. View southerly. |
Control Text
- 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 June 1991.
- 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.
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