Ernmark

Awesome article - thanks for resurrecting the thread!

Thought I'd bump this classic from wayback for those of you that have never run across it before - especially pertaining to edible benchmarks originally created by Zhanna here I tried it myself a few years ago with some success: (using powdered sugar instead of cornstarch/baby powder, etc. to 'dust') Great conversation starter with friends/office workers who are aware of your 'strange' hobby!

Note that KU1445 has SCALED coordinates - meaning that they were plotted on a map (although the vertical elevation will be very accurate). Other marks, like triangulation stations, will have ADJUSTED coordinates, meaning that they will be much more accurate (usually better that our consumer-grade GPSr will give). More detailed explanation will be given on Geocaching.com's benchmark FAQ page..

I remember reading (on their site, I believe) that the program, at least as marks were concerned ended in 200X. I haven't seen a recovery since...

Are you saying Triangulation Stations have this kind of accuracy, but ordinary adjusted benchmarks don't? Any horizontally adjusted mark will be very accurate. True 'benchmarks' usually have very accurate vertical information, but were 'scaled' horizontally (i.e., with a ruler on a USGS 7.5' topo map).. It is amazing how accurate most of these horizontal control marks are considering many go back to the 30s or earlier!

...remember that Horizonal Control stations (such as Triangulation Stations) would not need coordinates in the recovery as they have coordinates which are more accurate than our HH2 units. As DaveD mentioned above, marks with scaled horizontal coordinates are where we can help...

Although not under the Geocaching umbrella - they can be logged on Geocaching's sister site Waymarking.com under German Trigpoints and German Benchmarks

..at about that time members of the Power Squadron discontinued submitting reports as an organization. If I remember correctly it was a volunteer project to help with recovery reports as NGS is part of NOAA. A lot of recoveries tended to be near boating areas, but in my area, some members visited marks in the mountains/woods. Like us GEOCAC, some individuals were real serious about it and made detailed recoveries & some looked for the easy finds at the marina. Like one of the above posts mentioned, I've been all excited to climb a mountain to a mark not officially recovered since 1942, only to find bright pink tape, and some faded green tape, and more faded blue, etc..

There is a separate database maintained by NOAA which is more inclusive as not all tidals have made it into the NGS database - here's a link http://tidesandcurrents.noaa.gov - it would be hard to identify this particular one other than by reading the details of the sheets along the Eastern coast of FL (I'm assuming) & looking for a description of a standard USC&GS disk being used (rather than a NOS disk) and stamping of 'TIDAL NO 6 1960'. Hard to believe a disk would roll along the bottom of the seabed to one of the islands ...but stranger things have happened!

Thanks for the info everyone! As an aside, I recently was able to stop by the Point of Beginning (well technically 1112' north of it) on the OH/PA/WV border where the first survey of what was to become the US PLSS system began in 1785 - there's a nice (no-PID) monument there which was featured in Rhonda Rushing's book 'Lasting Impressions'. I was probably more impressed than my Daughters were

I have a picture of a PLSS marker located in Haw Creek Falls, Arkansas without the coordinates that go with it: Is it possible to figure out the coordinates where it should be? Closest coordinates given were probably within a few miles, I believe (N 35° 40.584 W 093° 15.324) - Being an Easterner, I'm not really up on the TWP/Ranges grid, although I've read over some of the charts

Did you note the link in the line after your trim of the 'sheet: The Local and Network Accuracy Data Sheet Program lna_ret Version 2.5 Date December 3, 2013 National Geodetic Survey, Retrieval Date = JULY 17, 2014 JV7206 ******************************************************************** JV7206 ACCURACIES - Complete network and local accuracy information. JV7206 DESIGNATION - DAVIS JV7206 PID - JV7206 JV7206 JV7206 Note that Horiz and Ellip values are accuracies at 95% confidence per JV7206 the FGDC accuracy standards. The values of SD_N, SD_E and SD_h are the JV7206 standard deviations (one sigma) of the coordinates (NETWORK) or JV7206 of the difference in the coordinates (LOCAL) in Latitude, Longitude JV7206 and Ellipsoid Height. The value CorrNE is the correlation JV7206 coefficient between the latitude and longitude components of either JV7206 the coordinate (NETWORK) or coordinate difference (LOCAL). The Dist JV7206 value is the three-dimensional straight-line slope distance, in km, JV7206 between station JV7206 and the corresponding Local station. Local JV7206 stations include any other station, regardless of distance, that JV7206 has been processed simultaneously with the station, in any project. JV7206 JV7206 Statistical information, in cm, follows. Correlation is unitless. JV7206 JV7206 Type/PID Horiz Ellip Dist(km) SD_N SD_E SD_h CorrNE JV7206 ------------------------------------------------------------------- JV7206 NETWORK 1.48 1.84 0.65 0.55 0.94 -0.03851109 JV7206 ------------------------------------------------------------------- JV7206 LOCAL (006 points): JV7206 JV7254 1.42 1.25 4.23 0.61 0.54 0.64 -0.18168922 JV7206 JV7215 1.48 1.25 5.12 0.64 0.56 0.64 -0.23513394 JV7206 JV7233 1.59 1.57 6.20 0.69 0.60 0.80 -0.08848601 JV7206 JV7242 1.60 2.18 7.47 0.71 0.59 1.11 -0.00521287 JV7206 JV7224 1.48 2.04 7.63 0.67 0.52 1.04 +0.09634709 JV7206 JV7196 1.39 1.80 11.21 0.62 0.50 0.92 +0.05439072 JV7206 JV7206 MEDIAN 1.48 1.69 6.83 JV7206 ------------------------------------------------------------------- ...interesting!

I fear it was the latter! PS - Episode one: 'Search for KW3100 '

I've run across that also - I think there was a bug that allowed that to happen with the older waymarks. I seems that the newer waymarks will automatically make the first upload the default, unless the poster selects a different on to make default.

Great idea - I've played Buzztime trivia ..we could make it on a weekday (Worldwide Waymarking Take off From Work Day!)

..and remember that the gc.com benchmark database pulled from the NGS was imported in 2000 and hasn't been updated since.

I post mine in Libraries

I believe they also could have held the position with a tripod set over the mark - you might want to post the question over in the Geocaching Benchmarking Forums as there are a number of professional surveyors that read/post there..

..you mean it isn't here?! I was robbed!

You'll also run into many stations where both the reset and original mark still exist and are in the NGS database..

I've seen similar posts & rectangular plates at 2 property corners at a church in PA - only ones I've ever seen until now

That's right - I remember Buckner Creel - I'll send a message thru GC ..y'never know - the info could still be out there somewhere! Thanks!

Just curious - I seem to remember that there was a page somewhere where all of this info was being collected in one place - can't find an active link anymore. Anyone remember?

..not to hijack this thread, but as an 'add on' - I've been noticing a lot of GEOCAC recoveries lately that are incorrect - some examples being a 2007 local agency reset being counted as a found good for a BM set in the 80s, an RM being counted as a lost tri-station, a horizontally adjusted mark which disappeared in the 1920s being found 100 feet away, etc. etc. (the three I mentioned were submitted by people who have found quite a few marks and are submitting them to NGS) A lot of us 'old-timers' remember picking on the US Power Squadron for making some less than stellar recoveries (it was a volunteer project they were involved in if I remember correctly) - I fear that 'GEOCAC' may get the same reputation with professionals if we aren't careful. For people who are just starting as BM hunters, it is best to wait awhile before submitting NGS recoveries & of course read these forums! And ask questions!

..so I'm not the only one! I have a few really old official highway maps (pre WWII) - no Interstates, US Highway numbers* gone for 50 years - a different world! * some referenced in NGS monumentation info