SL 129 — NGS AA8650 — Saint Louis County, US

USNGStrigunknown#7259
Latitude
38.799355°
Longitude
-90.208415°
Ellipsoidal h
132.55 m
Ortho h
163.90 m
Verifications
0
Last checked
Never
This triangulation station is part of the National Geodetic Survey network, which provides the foundational vertical and horizontal control infrastructure for surveying and mapping activities across the United States. Located in Saint Louis County, Missouri, at coordinates 38.79936°N, 90.20842°W, this trig point serves as a reference for precise geodetic measurements and local survey work. The triangulation methodology employed by NGS historically established networks of monumented points positioned to intervisibility standards, enabling surveyors to extend accurate positional control across regions. The ellipsoidal elevation of 132.5 meters contributes to three-dimensional spatial referencing capabilities. Verification and documentation of such reference points remain essential for maintaining survey integrity, supporting infrastructure projects, and ensuring consistency in coordinate systems. Professional surveyors rely on established networks to minimize cumulative positional errors in their work and to provide reproducible, traceable measurements tied to the national geodetic datum.

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SL 129 — NGS AA8650 — Saint Louis County, US is a triangulation station located in United States, catalogued in the US NGS dataset. The point has been assigned the stable identifier #7259 on SurveyingPedia and sits at an approximate elevation of 163.9 metres. Its coordinates in WGS84 are 38.799355°, -90.208415°, corresponding to 38° 47′ 57.68″ N, 90° 12′ 30.30″ W in the traditional degrees-minutes-seconds format. This page is a self-updating reference — all data is aggregated from public open sources and cross-checked periodically against the originating agency.

Professional surveyors, engineers, and topographers use points like SL 129 — NGS AA8650 — Saint Louis County, US to anchor total-station traverses, verify GNSS/RTK solutions, calibrate levelling instruments, and validate survey deliverables against known coordinates. The record on this page is refreshed daily via automated pipelines that monitor the public sources for any updates, corrections, or status changes.

Coordinate formats

WGS84 (decimal)38.799355, -90.208415
WGS84 (DMS)38° 47′ 57.68″ N, 90° 12′ 30.30″ W
UTM zone (approx.)Zone 15N (approx.)
Elevation163.90 m
Precise conversionOpen in coordinate converter →

Geodetic context in United States

The national geodetic reference in United States is maintained by National Geodetic Survey (NGS). The active datum is NAD83(2011) / NATRF2022 (active). Coordinates shown on this page are expressed in WGS84 (ETRF/ITRF-compatible) which is directly usable in most modern GNSS receivers. For cadastral work in United States you may need to convert to the local datum using the Coordinate Hub.

Browse the full list of indexed control points in United States from the country page.

Nearby benchmarks

The closest 6 indexed control points within roughly 50 km of this location:

US NGS · triangulation station
SL 19 — NGS AA8660 — Saint Louis County, US
3.1 km away · US
US NGS · triangulation station
SL 131 — NGS AA8653 — Saint Louis County, US
3.7 km away · US
US NGS · triangulation station
CSL 24 — NGS AA8584 — St. Louis, US
3.8 km away · US
US NGS · triangulation station
CSL 24A — NGS AA8585 — St. Louis, US
4.1 km away · US
US NGS · triangulation station
A 323 — NGS JC1184 — St. Louis, US
4.5 km away · US
US NGS · triangulation station
MODOT BELLEFONT CORS ARP — NGS DM3511 — Bellefontaine Neighbors, US
5.0 km away · US

Frequently asked questions

What is SL 129 — NGS AA8650 — Saint Louis County, US?

SL 129 — NGS AA8650 — Saint Louis County, US is a triangulation station located in United States, catalogued in the US NGS network. It has the public identifier #7259 and sits at an elevation of 163.9 metres. The point is used for geodetic reference, topographic surveys, and related measurement workflows.

Where are the exact coordinates of SL 129 — NGS AA8650 — Saint Louis County, US?

The position of SL 129 — NGS AA8650 — Saint Louis County, US in WGS84 is 38.799355°, -90.208415° (decimal), or 38° 47′ 57.68″ N, 90° 12′ 30.30″ W in degrees-minutes-seconds. For planar surveys in United States this falls approximately in UTM Zone 15N (approx.).

How can I reach and visit this triangulation station?

Use the satellite imagery above to see the surrounding area. You can open this location directly in Google Maps, Google Earth, Bing Maps, or OpenStreetMap using the buttons provided. Many geodetic points are accessible to the public; some are on protected or private land — check local regulations before any field visit. Always bring documentation or your credentials if you plan to use the marker for professional measurement.

Is this point verified and usable for professional surveying?

This record has been community-verified 0 times. Data quality depends on the source: NGS and official national agency points are typically centimetre-accurate, OpenStreetMap survey points are metre-accurate, and GeoNames topographic landmarks (peaks, hills) are reference-grade only. Always cross-reference with the original agency datasheet before using this point for cadastral, legal, or safety-critical work.

Original source: this record was imported from ngs_public. Always refer to the original datasheet for the most up-to-date and authoritative data.