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Details for Benchmark: JZ0857

N 39° 20.067 W 084° 30.583 (NAD 83)

Altitude: 638.23

Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)

Location:
In BUTLER county, OH View Original Datasheet
Designation:
G 4
Marker Type:
chiseled square
Setting:
massive structures
Stability:
Probably hold position/elevation well.

Must Read!

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Logging a note to remind myself to take this one off my list of "to look for" when I am in Fairfield area. Today was the second time in as many years that I went to search for this BM only to realize I had looked for it in the past and realized it is not doable without some very precarious climbing, hacking thru vines (most likely P. Ivy) to reach the top of the overpass. I'm leaving this one to the locals for recovery.

Documented History (by the NGS)

Unknown by CGS (MONUMENTED)
01/01/1947 by NGS (GOOD)
DESCRIBED BY NATIONAL GEODETIC SURVEY 1947 5 MI SE FROM HAMILTON. 5.0 MILES SOUTHEAST ALONG THE BALTIMORE AND OHIO RAILROAD FROM THE STATION AT HAMILTON, ABOUT 5.4 MILES NORTHWEST OF THE STATION AT GLENDALE, AT OVERPASS NO. 204 OVER PORT UNION ROAD, A SQUARE CUT IN THE TOP OF THE FIRST COURSE OF STONE BELOW THE CONCRETE BRIDGE SEAT IN THE NORTHWEST ABUTMENT, 14 FEET NORTHEAST OF THE NORTHEAST RAIL, AND 7.5 FEET BELOW THE TRACK.

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.