Skip to Content

Details for Benchmark: AE9197

N 41° 52.683 W 091° 38.800 (NAD 83)

Altitude: 775.02

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

Location:
In LINN county, IA View Original Datasheet
Designation:
2713
Marker Type:
bench mark disk
Setting:
retaining walls, concrete ledge, etc.
Stability:
May hold, but of type commonly subject to surface motion.

Must Read!

Benchmarks may be on private property or in dangerous locations. Obey local laws. By using the services on Geocaching.com you agree to this disclaimer.

Good condition, as described.

[Photos:]
photoAE9197-2713-3N-20170531.jpg
.

Found in good condition Linn Co Engineering Dept disk 2713, brass with flat top 4 inch diameter plus bevel. Handheld coordinates N41 52.666 W091 38.800, sky visibility marginally ok. I would describe it as being in the concrete bridge railing 1.6 feet north of the point where it meets the abutment concrete railing.

This is a slightly unusual design; see picture. You can approach this (with minor caution about your footing) in reasonable safety from the southwest, to avoid being on the very busy bridge, but may need to stand on something if you are short.

[This entry was edited by Bill93 on Thursday, October 14, 2004 at 6:20:30 PM.]

[Photos:]
photoAE9197_20040917_C.jpg

Found as described. Pictures and waymarks to follow.

Documented History (by the NGS)

Unknown by IA-113 (MONUMENTED)
01/08/1998 by NGS (GOOD)
DESCRIBED BY NATIONAL GEODETIC SURVEY 1998 (GAS) 0.3 KM (0.20 MI) NORTHERLY ALONG ROSE AVENUE FROM THE POST OFFICE IN SWISHER, THENCE 4.0 KM (2.50 MI) EASTERLY ALONG DIVISION STREET AND COUNTY ROAD F-12, THENCE 3.4 KM (2.10 MI) NORTHERLY ALONG CLUB ROAD, IN TOP OF AND 0.5 M (1.6 FT) NORTH OF THE SOUTH END OF THE SOUTHWEST CONCRETE ABUTMENT GUARDRAIL OF A BRIDGE SPANNING SOUTH HOOSIER CREEK, 5.1 M (16.7 FT) WEST OF THE ROAD CENTER, AND 0.9 M (3.0 FT) ABOVE THE LEVEL OF THE ROAD.

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 September 2000.
  • 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.

Advertising with Us

Return to the Top of the Page