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Details for Benchmark: RD4331

N 45° 21.738 W 122° 36.731 (NAD 83)

Altitude: 188

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

Location:
In CLACKAMAS county, OR View Original Datasheet
Designation:
EPF 11
Marker Type:
horizontal control disk
Setting:
mat foundation, concrete slab, etc.
Stability:
May hold, but of type commonly subject to surface motion.

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Found in good shape with Papa-Penguin. Pictures are in his log.

Another one found rather easy and in good shape!

[Photos:]
photoThe area
photoRD4331

Found it

found RD4331

[Photos:]
photowest Linn or.
photolooking so.

nice drive.

[Photos:]
photoBenchmark in West Linn, OR

easy find

Easy find.

Tricky dodging traffic at crazy intersections but easy once we got there. . . . patrick & shirley

[Photos:]
photoRD4331

Documented History (by the NGS)

01/01/1983 by ORHD (MONUMENTED)
DESCRIBED BY OREGON HIGHWAY DEPARTMENT 1983 (JDU) THE STATION IS LOCATED 0.05 MILE WEST OF OREGON CITY, WITHIN THE CITY LIMITS OF WEST LINN AND ALONG INTERSTATE 205. TO REACH THE STATION FROM THE WEST END OF THE WILLAMETTE RIVER BRIDGE FOR INTERSTATE 205, GO SOUTHWEST FOR 0.1 MILE TO THE BROADWAY OVERCROSSING AND THE STATION. THE STATION IS A STANDARD ORHD DISK STAMPED---EPF 11 1983---, SET INTO A DRILL HOLE IN THE SIDEWALK AT THE NORTHEAST CORNER OF THE STRUCTURE. 15.20 METERS (49.87 FT) SOUTH FROM THE METAL HAND RAIL.

Control Text

  • The horizontal coordinates were established by classical geodetic methods and adjusted by the National Geodetic Survey in October 1991.
  • The NAVD 88 height was computed by applying the VERTCON shift value to the NGVD 29 height (displayed under SUPERSEDED SURVEY CONTROL.)
  • The Laplace correction was computed from DEFLEC99 derived deflections.
  • The geoid height was determined by GEOID99.

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