boundsgoer
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Posts posted by boundsgoer
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I did have one nagging question though........ The NE/KS baseline is supposed to be at 40 degrees North, correct? Why would my GPS show the marker that was placed about 314.1 feet north of that point? My GPS showed 40 00 03.1 N +/- 7 feet. I heard Lynn (Linn ? Lin?) mention the same thing.
I also visited the 6th Principal Meridian 48 miles to the west. Placed on the disc, my GPS read 40 00 07.1 N +/- 7 feet. At that point the state line (base line) would be 719.4 feet south.
What's up with that? Or is the baseline not actually at the state border of 40 North?
Probably because 700+ feet is pretty good considering the methods used and equipment available 150 years ago.
That is why the GLO/BLM rules state that absent fraud the position of the monument holds over where it is "supposed" to be. Otherwise, the monument would move every time a more accurate method comes along.
General surveying principles hold that an original monuments position will prevail over bearing and/or distance.
Think about if your lot was first subdivided in 1930 with monuments set at each corner. In 1975 with the newfangled Electronic Distance Measuring (EDM) device I can measure more accurately than the transit and chain used in 1930 and determine the original monuments should be 0.3' west. In 2005 with my $50,000 GPS equipment I determine the monuments should really be 0.5' east.
I cannot move monuments just because I can measure more accurately than my predecessor. Think about the problems with buildings, improvements, etc. that can cause.
Up in the mountains west of where I am, if we find monuments within a foot where the plat says they should be, we are doing really good. Even a couple of feet is normal. A lot of these subdivisions were done in the 1960's and 1970's. They did the best they could given the methods, equipment and terrain.
So the state line is going to be the line as monumented, not necessarily as described.
There have been several lawsuits between states because of this.
Texas and New Mexico are arguing over a portion of thier common line which is a couple of miles from where it is "supposed" to be. Look in the area where Texas, New Mexico and Oklahoma come together. If I remember correctly, the boundary between Texas and New Mexico was supposed to be 103 degrees longitude. Where the surveyor determined the line to be was too far west and staked this line going south.
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Here is one NGS did not find back in 1983 (JK0195). Maybe it was covered up with snow and/or a pile of junk.
The original call was "4 rails" northwest of Milepost 91. Milepost 91 is still in place and looks like it is in the original position. I measured 144 feet. It looks like for this particular mark a rail was 36 feet. The rail has been replaced with continuous (ribbon) rail so I could not measure the length of a rail.
According to the landowner, surveyors come out to this mark all the time. I am going to try to get the word out among the bretheren to log a recovery on the NGS site when they find a bench mark or control point.
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It appears to me the monument is marking a corner of a mineral survey (MS 16537). I cannot begin to guess what "MS SD G2 & 591" would mean. I have only performed a couple of mineral survey retracements and have marked the caps with just my PLS number, year the survey was done, Mineral Survey number and corner number.
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Me & Bucky (or would that be You & Bucky)
Regarding OTIS and OTIS 2, look at the email correspondance below I had with the NGS about these two points back in 2001:
Hi Mark! This point was recently (within the last year) observed again with GPS and again, as in 1991, it was determined that OTIS (LK0571) had somehow moved and the original position was no longer correct. OTIS 2 (LK0789) is the point redetermined by the GPS observations and this position should be used in all field work. We could not determine if the original post had been uprooted, or if the original observations were bad.
Burton Smith
NGS, N/NGS43 Records Management Branch
(301) 713-3184
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Subject: Discrepancy with C&GS station
Date: Mon, 21 May 2001 11:21:15 -0600
From: "Mark Johannes" <mark@clarklandsurveying.com>
Organization: Clark Land Surveying
To: "Deb Brown" <Deb.Brown@noaa.gov>
Coordinates from your data sheet for Station "OTIS" (PID LK0571) and for "OTIS 2 (PID LK0789) show the two monuments approx. 7.5 feet apart. The monument in the field stamped "OTIS 1935" appears to be in the location of "OTIS 2" as described in the data sheet. Using the reference marks for "OTIS", it appears to me that this is the case. Is it possible that when the crew went out to set "OTIS 2" prior to GPS observations that they found "OTIS" still in concrete which was torn out during expansion of the cemetery? Could they have simply reset "OTIS". Please do not hesitate to contact me if you need additional information, or if you are able to determine what happened. Thank you, Mark Johannes, PLS
Clark Land Surveying, Inc.
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Check out THIS THREAD from a few weeks ago about bearing trees.
- Kewaneh
Yeah, I remember that thread. I was asking about USGS bearing trees, though. I have never heard of USGS marking bearing trees to reference their monuments.
Way too inaccurate, even for USGS.
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Do you have any pictures of the USGS bearing trees? I have never heard of such a thing being done by them.
I wonder if there are any here in Colorado.
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Right next to a bearing tree, so easy to find.
Since it was near a bearing tree, I suspect it is actually a Section corner monument, not a bench mark or control point.
evenfall,
Bearing Trees are used most by the BLM (f.k.a. the GLO) as references to section corner monuments set by them.
NGS sets reference monuments for their control points, not bearing trees, as bearing trees are not very accurate to use for replacing control points.
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I was struck by the BLM markers that were brass on iron pipes and the fact that the metals interact and destroy each other. That may explain some of the older missing marks.
I don't know about that. I have found GLO (nka BLM) markers from 1908 that were in pretty good shape.
Maybe the local soils and environment have an effect on them.
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The "xxxx" typically refers to the elevation of the Bench Mark to the nearest foot.
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I case you haven't done so, try to find out if that witness post has been broken off and stuck back in the ground, making it look like the ground has been filled in substantionally.
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I believe most of the 1 mile corners they tried to get in the center of the County or other Roadways.
GEO*Trailblazer,
I believe you have it backwards. Generally, the section lines were established first and roads were usually built on the section lines.
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Try going to surveyhistory.org and contacting the curator for information.
I had them research a "wye" level my parents had purchased at an auction.
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I would NOT log FZ1197 as destroyed. According to the datasheet, there is an underground mark in place. A person could use the underground mark to reset the surface mark.
If I was to log this one on the NGS site, I would note it as "Poor, Requires Maintenance" with a note on what was found.
As a surveyor looking for survey control in the area, I would need to make the determination as to whether what was remaining was "good enough" for my purposes.
As far as GA1396, I concur with Rich in NEPA. Since you cannot prove that what you found is the bench mark, you cannot say it is destroyed.
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I have surveyed over 100 monitoring wells and have seen many that look like the one in the pictures. Inside the sqaure tube is a PVC pipe, which is the actual well.
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I cannot believe some of the inane descriptions, such as ". . .first driveway beyond a farmhouse owned by Dick Powell. . ." What were they smoking when they wrote that? Were these written to be good for only a few years? That piece of land, by the way, is now a hot air balloon field owned by the National Balloon Classic. I could probably actually do some research and asking around and find somebody who remembers the farmhouse, but does a professional surveyor have time to do all that? See, your tax dollars were "hard at work" even back then!
Last July I recovered RN0954, which was set in 1898. The original to reach referenced "Mrs. Foulds" house.
The Foulds family stills owns that house. In that case, it helped me in locating the monument.
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As a Professional Land Surveyor, I use these Traverse Stations and Bench Marks on a regular basis.
Many of my projects need to be tied into a known datum.
These marks are still very important. They were not established just for the purpose of preparing maps. They are needed to determine exactly where on the globe a particular property or structure is located.
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I have seen highway plans that show the letters POST on it with a station (i.e. 123+45.6). I believe POST stands for Point On Straight Tangent.
Perhaps this sign is intended to reference a particular highway station.
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Most of the bench marks and station marks I have logged on Geocaching.com I have recovered during a survey.
I do keep my eyes open while I travel, though.
Also, if I am going on vacation, I will download control point information for the area I will be staying in.
Even if I recover a point for fun, I will log it on the NGS website.
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quote:
This 1887 survey began at bench mark A in Hagerstown, Md.Check out JV3199. This is bench mark "A" referred to above.
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These are the results of my latest out of town job last Thursday and Friday (Sept. 25 & 26):
1 bench mark found and 5 tri stations not found.
And I did not even need the bench mark for my survey work. I went to look for it since I was in the area.
Since I did not find any of the station marks, I will have to post-process my data. Not a big deal.
The PID's (if anyone is interested) are as follows:
HK0089
HK0473
FO1208
FO1216
FO1104
FO1111
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Here is something I came across on a Land Surveyors message board:
"I had always thought the original 'Mile High Marker' set on the steps of the Colorado State Capitol was done in approximately 1930-1931. Turns out it was much earlier, 1909. That got me to wondering what datum that was on and when the first cross country network was finished. This all led me to an excellent article published in POB which I vaguely remembered. Got lucky and found it. Without POB's permission, here is part of that article.
'History of U.S. Geodetic Vertical Datums' by David B. Zilkoski, 10/18/2000
'The first leveling route in the United States considered to be of geodetic quality was established in 1856-57 under the direction of G.B. Vose of the U.S. Coast Survey. The leveling survey was required to support current and tide studies in the New York Bay and Hudson River areas. The first leveling line officially designated as "geodesic leveling" by the Coast and Geodetic Survey followed an arc of triangulation along the 39th parallel. This 1887 survey began at bench mark A in Hagerstown, Md.
By 1900, the vertical control network had grown to 21,095 km of geodetic leveling. A reference surface was determined in 1900 by holding elevations referenced to local mean sea level (LMSL) fixed at five tide stations. Data from two other tide stations indirectly influenced the determination of the reference surface. Subsequent readjustments of the leveling network were performed by the Coast and Geodetic Survey in 1903, 1907 and 1912.
The next general adjustment of the vertical control network was accomplished in 1929. By then, the international nature of geodetic networks was well understood, and Canada provided data for its first-order vertical network to combine with the U.S. network. The two networks were connected at 24 locations through vertical control points (bench marks) from Maine/New Brunswick to Washington/British Columbia. Although Canada did not adopt the "Sea Level Datum of 1929" [name changed to National Geodetic Vertical Datum of 1929 (NGVD 29) in 1973] determined by the United States, Canadian-U.S. cooperation in the general adjustment greatly strengthened the 1929 network."
So, I conclude the U.S. was on the 1907 version of the national datum at the time of the setting of that original BM.
Bill McComber, PLS CO
Bill is a knowledgeable fellow, so I trust his conclusion.
Mark
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Clicked on "post now" twice.
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You may be able to scale the coordinates from a topo map that shows a USLM.
I would go to your BLM office to research the USLM's in your area.
Please note that any Lat/Long shown on the old plats are accurate given the instrumentation available. Of course, newer USLM's will have more accurate Lat/Longs.
BUT, the actual position of the monument is what matters to surveyors, not necessarily the coordinates.
The BLM records will also show what type of monument was used. Could be anything from a stone, wood stake or brass disk.
Sounds like fun trying to find one of these monuments.
One other comment:
USLM's were generally set because the Public Land Survey System (PLSS) either had not or was not going to come to the area. Sometimes the PLSS came through later.
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I try to keep a new “to reach” as clear as possible. Note new mileages from intersections, distances from improvements (buildings, fences, etc). I omit calls to features far away, such as a Railroad Depot. All that previous information is available on the data sheet. Additionally, I think most people will plot the position on a quad map available online in order to get them in the ballpark.
I would note in the “to reach” for the station mark that there is a new “to reach” for each of the related marks. This should direct people to then download those data sheets.
Remonumenting A Meridian Stone
in Benchmarking
Posted
That is partially true. Some state borders were intended to be along a certain (not necessarily arbitrary) line of latitude or longitude. The discrepancy happens because the original surveyor did not get exactly on the line he was supposed to.
You a correct that the monuments themselves become very important because they mark where the line was established on the ground.