Corps of Engineers Survey Mark C-121, Marin County, CA. Find it and you’ll find a rare VORTAC^1 (ht: @therunetarian) #latergram #nofilter Hint: find the view from the previous photo (tantek.com/2016/290/t1/bridge-bridge-view-trail-run-sfrc) then #lookdown around your feet and be careful not trip on a short metal flag in the ground with C-121 etched into it. For the previous “mark” (tantek.com/2016/284/t3/coyote-ridge-2-horizontal-control-mark) I found a single online result (until I blogged about it, then more showed up afterwards). This time, I tried searching for "Corps of Engineers" "Survey Mark" "C-121" https://www.google.com/search?q=%22Corps+of+Engineers%22+%22Survey+Mark%22+%22C-121%22&ie=utf-8&oe=utf-8 and got two results, a PDF from Washington State Legislature, and an Internet Archive of a periodical index, neither applicable. I tried searching for "Corps of Engineers" "Survey Mark" Marin 1957 (all phrases words on the physical mark itself) https://www.google.com/search?q="Corps+of+Engineers"+"Survey+Mark"+Marin+1957 and got two pages of results, none of them about this mark in particular, but I did find a fascinating PDF of a 1980 document: “Input Formats and Specifications of the National Geodetic Survey Data Base / Volume I. Horizontal Control Data” https://www.ngs.noaa.gov/FGCS/BlueBook/pdf/Chapter1-2-3--1980.pdf So for the next person that comes across this survey mark, here’s the full text, roughly in the order and phrases intended on the mark: CORPS OF ENGINEERS – U.S. ARMY SURVEY MARK $250 FINE OR IMPRISONMENT FOR DISTURBING THIS MARK MARIN 30TH ENGR GP STATION DESIGNATION AGENCY YEAR 1957 (Known typos: CORP OF ENGINEERS) According to Google Maps (dropping a pin in satellite view) the latitude longitude coordinates of this Marin County mark are: Latitude: 37.8556 degrees (N) Longitude: -122.5221 degrees (W) Altitude: 1040 feet I need to get a GPS watch (or an https://aaronparecki.com/) to record more precision. No luck searching on geocaching.com/mark either — nearest benchmarks they had were 1.3 miles away. ^1 https://en.wikipedia.org/wiki/VORTAC https://irs2.4sqi.net/img/general/width960/476_V-CavS2umxuwVizihzcjj7e9ET4mbs6HDd9POIgENbw.jpg https://foursquare.com/v/faa-vortac/4e1268dcae602afe96c5efc5?openPhotoId=58026574d67ce59c29d6b37b #seenonmyrun #trailrun #corpsofengineers #army #armycorpsofengineers #surveymark #permalink #marin #ca #gottacatchemall

Corps of Engineers Survey Mark C-121, Marin County, CA. Find it and you’ll find a rare VORTAC¹ (ht: @therunetarian) #latergram #nofilter

Hint: find the view from the previous photo (tantek.com/2016/290/t1/bridge-bridge-view-trail-run-sfrc) then #lookdown around your feet and be careful not trip on a short metal flag in the ground with C-121 etched into it.

For the previous “mark” (tantek.com/2016/284/t3/coyote-ridge-2-horizontal-control-mark) I found a single online result (until I blogged about it, then more showed up afterwards).

This time, I tried searching for "Corps of Engineers" "Survey Mark" "C-121"

https://www.google.com/search?q=%22Corps+of+Engineers%22+%22Survey+Mark%22+%22C-121%22&ie=utf-8&oe=utf-8

and got two results, a PDF from Washington State Legislature, and an Internet Archive of a periodical index, neither applicable.

I tried searching for "Corps of Engineers" "Survey Mark" Marin 1957 (all phrases words on the physical mark itself)

https://www.google.com/search?q="Corps+of+Engineers"+"Survey+Mark"+Marin+1957

and got two pages of results, none of them about this mark in particular, but I did find a fascinating PDF of a 1980 document:

“Input Formats and Specifications of the National Geodetic Survey Data Base / Volume I. Horizontal Control Data”
https://www.ngs.noaa.gov/FGCS/BlueBook/pdf/Chapter1-2-3--1980.pdf

So for the next person that comes across this survey mark, here’s the full text, roughly in the order and phrases intended on the mark:

CORPS OF ENGINEERS – U.S. ARMY SURVEY MARK
$250 FINE OR IMPRISONMENT FOR DISTURBING THIS MARK
MARIN 30TH ENGR GP
STATION DESIGNATION AGENCY
YEAR 1957

(Known typos: CORP OF ENGINEERS)

According to Google Maps (dropping a pin in satellite view) the latitude longitude coordinates of this Marin County mark are:
Latitude: 37.8556 degrees (N)
Longitude: -122.5221 degrees (W)
Altitude: 1040 feet

I need to get a GPS watch (or an https://aaronparecki.com/) to record more precision.

No luck searching on geocaching.com/mark either — nearest benchmarks they had were 1.3 miles away.

¹ https://en.wikipedia.org/wiki/VORTAC

#seenonmyrun #trailrun #corpsofengineers #army #armycorpsofengineers #surveymark #permalink #marin #ca #gottacatchemall