tosborn

Andy: RK0533 isn't in either list because it was reported to NGS as destroyed. In my case, digital datasheet aren't provided in the State archive shapefiles for destroyed marks.

>>For MI, I got this list (I checked the first 3 and only 1 of them is in tosborn's list): Black Dog: In Michigan did you seach the whole State or only the upper peninsula? For Michigan my list is just for the upper peninsula. Also, I noticed two records in my list that are not lookout towers, but had "lot" in the names...."Charlotte River MI - RJ1321" and "Blotch WI - PO0576" so those two can be disregarded.

I don't think there is a really simple direct way to do what you want. However, one could download the State Archive files from NGS for Wisconsin and Michigan, eliminate all records in Michigan except the UP, and then search for any remaining record in Wisconsin or Michigan in which the name of the record contained "LOOKOUT" or "LOT" (short for lookout tower). Then one would know the locations of most of the lookout towers (mainly intersection stations) that are in the NGS database and one could then do a radial search from them to find nearby benchmarks. I've gone ahead and located all the "LOOKOUT" or "LOT" records (163 of them) in Wisconsin and the UP of Michigan currently in the NGS State Archive shapefiles. At the following link is a comma-separated-values (csv) file with their PIDs, State, County, Lat, and Long that you can download. LINK Good Hunting!

Kewaneh: We are in complete agreement about what it takes to do a credible retracement survey. What seems to be different is that in your area the PLSS corners are well monumented and documented and the surveyors don't take shortcuts. In my area, PLSS corners are poorly monumented/documented and many surveyors see no problem with holding a P-K nail, cotton spindle, railroad tie, or even just a tone from their magnetic locator, as marking the corner, and the idea of excavating asphalt to verify a corner is a foreign concept. I'm sorry you got the impression that I was implying that the point of the Penry article was that ANY use of a magnetic locator was a poor practice. If I believed that I wouldn't own a magnetic locator. I should probably have been more specific. What I was trying to communicate was that solely using a tone from a magnetic locator to "define" a corner without further investigation was a poor practice. That's what the figure in the Penry article demonstrates. In that example the surveyor, based ONLY on a tone from his locator (Step 4) has set a P-K nail in the asphalt and proceeds to do a GPS occupation. What the surveyor has actually identified is the approximate location of an unseen rebar under the ashphalt that is directly over the end of a bent pipe that is some distance from the original quarter corner stone. I'm glad to hear that you don't engage in such practices. Apparently Penry has observed such practices or he wouldn't have written the article. It would be great if it were true that "the professional practices of the surveying community at large will regulate that surveyor out of the business." Unfortunately, it can take a very long time for such a process to occur, if ever, and in the mean time a lot of damage can be done to the public through inaccurate surveys. Two years ago the State Surveyor of Arkansas proposed to update the State Minimum Standards...the first change since 1996. The biggest change would have required surveyors to properly monument controlling 1/16th corners, 1/4 corners, and Section corners shown on their plats and file a Certified Corner Record (CCR), UNLESS a CCR was already on file and the found monument and accessories agreed with the Record. The Arkansas Society of Professional Surveyors supported the changes. However there was a violent negative reaction by the rank and file who complained that such requirements were unnecessary and would drive-up the costs of property surveys. In response, a State Senator, himself a retired surveyor whose son is a practicing PLS, set about what some have characterized as the gutting of the Office of the State Surveyor. The result was the shelving of the update to the Minimum Standards and the resignation of the State Surveyor. Afterward, the president of the Arkansas Society of Professional Surveyors stated “It is going to be a lot easier for a practitioner who wants to do substandard work to get away with it.” This in a state where many believe it was already easy to get away with substandard work. (see http://www.nwanews.com/adg/Editorial/189521/print/) With regard to the OP....I, like you, don't know for sure if the center-punched disk he found is a PLSS corner or not. I only suggested that it appeared to me that it could be based on the location which is where the North quarter corner of Section 36 would be approximately located. In your area, such a mark apparently wouldn't likely be a PLSS corner. In my area, such a monument would be a more substantial mark that 95 percent of the various P-K nails, cotton spindles, etc out there marking PLSS corners. Maybe the OP will excavate and tell us if he finds an original stone.

Kewaneh: You must have missed Jerry's step #4 in his figure where it says 'PK Nail set in asphalt after using the magnetic locator to “define” the position of the (unseen) Rebar below.' In addition to the points you mentioned, Jerry is saying that using a magnetic locator soley to "define" the position of an unseen monument is poor practice. The tone you get could be any piece of ferrous trash under the asphalt, or it could be what you are looking for but significantly displaced by snowplows or other road machinery like the iron pipe in the figure. Only by using the pick and shovel will you be able to verify what you have found and whether it accurately represents the original corner. Unfortunately it's my experience that too few surveyors these days are willing to invest the time, energy, and expense to use the pick and shovel particularly when it means coordinating with the city to close a street, excavate under the asphalt, and then repair the street. The prevailing attitude seems to be to whip out the Schoenstedt, get a tone, paint a dot, and you can be on to the next job that much sooner, and no need to get involved with remonumentation or the filing of a certified corner record. It's this improper use of the magnetic locator that I was referring to, not the use of magnetic locators in general. As you may know, Jerry Penry is very much an exception to this trend. Some of his efforts to recover, monument, and lower original GLO stones are recounted at rpls.com and on his website, and are examples of the way it should be done.

Above I mentioned how some surveyors "locate" unseen corners beneath asphalt using their magnetic locators (e.g. Schoenstedt). This is a very poor practice as Jerry Penry illustrated in the July 2003 issue of Professional Surveyor Magazine. See the 1 page pdf at http://www.profsurv.com/pdf/archives/psm_2...y_surveying.pdf

Around here (NW Arkansas), you are very lucky if you find a stamped tablet representing a PLSS corner. For example, the section in which I live has only two stamped tablets...one at the NE section corner and one at the North quarter corner. The center quarter corner is monumented with a cotton spindle set in the asphalt of a residential street. The 16th corner just West of me is monumented by a P-K nail set in asphalt. The south quarter corner was monumented with a railroad spike set in the asphalt until 1982. It was then replaced with a stamped tablet set flush with the asphalt, which has not been seen since 1993. To locate this corner today, local surveyors whip out their Schoenstedts and put a spot of paint on the asphalt where they get the loudest tone. The SE section corner was proportioned in the mid-1980's and is in conflict with previous recorded property surveys and longstanding lines of occupation. There are generally no underground monuments upon which to rely and of course the original 1831 bearing trees have long since disappeared, as have the bearing trees from the 1980 perpetuations. In general it's a sorry state of affairs.

Geosym: I don't know. It's possible that your mark could be a PLSS corner. If so it would most likely be the NE corner of the NW quarter of the SE quarter of Section 32, , Township 21N, Range 3E of the Willamette Meridian, but it could be something else entirely. The "88" painted next to it is probably important. Is there an "87" or an "89" 100 feet up or down the street?

Based on its location, it appears that this disk monuments the north quarter corner of Section 36, Township 30N, Range 22W, 4th Principal Meridian Extended, in the Public Land Survey System (PLSS). As such, it would be a cadastral survey marker serving a role in the delineation of property boundaries and is probably not a "benchmark." In the PLSS states, a marker at the intersection of two roads, one running north-south, and the other running east-west, will often be marking a section corner or quarter corner. Inspection of a topographic map of the area usually can help determine if a PLSS corner is/should be located nearby.

A very entertaining read! Thanks for the descriptions and photos. This is really impressive work.

Here's a method to do what the original poster wants to do with a GPS receiver and a compass. It should work with mapping and non-mapping GPS receivers as long as they have a "Project Waypoint" capability. 1) Record a waypoint at your first location...call it "A". 2) While still at "A" take an azimuth on the distant point with the compass. Using the "Project Waypoint" feature of the GPS (for example on the Garmin 60CSx), project a new waypoint from "A" using the azimuth just determined and a distance large enough to extend well beyond the distant point. Call the newly projected waypoint "B". 3) Go to another location where the distant point can observed and record a waypoint there...call it "C". 4) While still at "C" take an azimuth on the distant point. Using the "Project Waypoint" feature of the GPS project a new waypoint from "C" using the azimuth just determined and a distance large enough to more than extend beyond the distant point. Call the newly projected waypoint "D". 5) Create a route in the GPS using waypoints in the following order: A, B, D, C. The point where the route crosses itself is the location of the distant point. Zoom in and create a waypoint at the point of crossing. If your compass is not corrected for magnetic declination, make sure your GPS 's "North Reference" is magnetic. Of course, you could also do the math for an Azimuth/Azimuth Intersection (Foresection) if you also bring along a calculator or laptop.

The Magnetic Station near me (GG0638) also has no markings other than a punch mark in the center of the double triangles. Perhaps Mag Stations have no other markings.

They are all located within Philmont Boy Scout Ranch in Northern New Mexico. That's why I provided a link to Philmont waypoints.

I have a list of Philmont waypoints at http://www.lepp.cornell.edu/~seb/philmont-gps.txt From there can be obtained the following lat-long coordinates: Hart Peak 36.62785 -105.02366 Trail Peak 36.40733 -105.06702 Black Mountain 36.44958 -105.08210 You can then take those coordinates (leaving off the negative sign in front of longitude) and enter them into the radial seach for datasheets at http://geodesy.noaa.gov/cgi-bin/datasheet.prl This will give you the PID's for the monuments (if any) and you can then enter the PID's under "Find a Benchmark" at http://www.geocaching.com/mark/ Hart Peak PID=GM0771 Trail Peak PID= nothing shown in the NGS datasheet database near those coordinates, and nothing shown on USGS topo maps Black Mountain PID=GM0785 If there are any photos of these monuments, they would most likely be at http://www.geocaching.com/mark/ Hope that helps Tim

www.usps.org

The disk looks similar to the American Legion logo (star and garland). Also, it appears that under the star are the letters "A. L. A.", which could stand for American Legion Auxillary.

That's true for Hatley...I see it there. Also on the Ringle, Wisconsin 7.5 minute quad. But, although I haven't done an exhaustive search, the associated 15 minute map is not indicated on the 7.5 minute maps I looked at in Arkansas and New Mexico. I wonder why the difference? Maybe it's just a Wisconsin thing?

If you can do this for the entire U.S., it would be extremely helpful (and I will be eternally grateful)! ~Zhanna That's what I'm planning. Tim

A couple of weeks ago I contacted USGS and asked if they had an electronic index (shapefile, etc) of the old discontinued 15 minute (1:62,500) map series for the U.S. They responded that they do not. I am working on a way to develop such an index and hope to be able to make it available in the next couple of weeks. It would show the 15 minute series geographic extents and names along with the current 7.5 minute quads covering the same area.

ArtMan: The GeoPDF's, just like DRG's they are made from, are subject to the same National Map Accuracy Standards. In terms of horizontal accuracy, for maps on publication scales of 1:20,000 or smaller, this means that not more than 10 percent of the well-defined points tested can be in error by more than 1/50 inch. For a 1:24,000 scale map this translates to 40 feet. So while the GeoPDF technology allows one to get the coordinates of a tri-station or a BM as its shown shown on a map more accurately than scaling with pencil and ruler, 90 percent of the time the position shown on the map could be off by as much as 40 feet, and 10 percent of the time it could be off by more than 40 feet from where the tri-station or BM is located in the real world.

NGS hasn't fully adapted to the new format either....now, if you download a shapefile for a PID that has been updated to NSRS2007, a lot of the fields including Lat Long are messed-up.

Here's the first part of what one of the new NSRS2007 Datasheets looks like with the absolute accuracy estimates: AE2999 *********************************************************************** AE2999 CBN - This is a Cooperative Base Network Control Station. AE2999 DESIGNATION - OLD MAIN AE2999 PID - AE2999 AE2999 STATE/COUNTY- AR/WASHINGTON AE2999 USGS QUAD - FAYETTEVILLE (1995) AE2999 AE2999 *CURRENT SURVEY CONTROL AE2999 ___________________________________________________________________ AE2999* NAD 83(NSRS2007)- 36 04 05.11033(N) 094 10 11.98402(W) ADJUSTED AE2999* NAVD 88 - 433.9 (meters) 1424. (feet) GPS OBS AE2999 ___________________________________________________________________ AE2999 X - -375,351.031 (meters) COMP AE2999 Y - -5,148,217.555 (meters) COMP AE2999 Z - 3,734,539.992 (meters) COMP AE2999 LAPLACE CORR- 1.03 (seconds) DEFLEC99 AE2999 ELLIP HEIGHT- 405.911 (meters) (02/10/07) GPS OBS AE2999 GEOID HEIGHT- -28.01 (meters) GEOID03 AE2999 AE2999 ------- Accuracy Estimates (at 95% Confidence Level in cm) -------- AE2999 Type PID Designation North East Ellip AE2999 ------------------------------------------------------------------- AE2999 NETWORK AE2999 OLD MAIN 0.88 0.71 2.59 AE2999 ------------------------------------------------------------------- AE2999 LOCAL FG1941 CLARPORT 1.04 0.80 3.04 AE2999 LOCAL GF1020 HOMEPORT 1.12 0.90 3.33 AE2999 LOCAL FG1957 OZARPORT 0.90 0.73 2.65 AE2999 LOCAL GF1026 ARP 2 1.12 0.90 3.29 AE2999 LOCAL FH1262 POCOLA 1.08 0.84 3.14 AE2999 LOCAL AE2989 AGRONOMY 1.14 0.92 3.37 AE2999 LOCAL AE2997 ENGINEERING EXPERIMENT STATION 1.16 0.90 3.39 AE2999 LOCAL AE3011 W H PHILLIPS 1.00 0.78 2.94 AE2999 ------------------------------------------------------------------- AE2999 LOCAL AVERAGE 1.07 0.85 3.14

As mentioned by GEO*Trailblazer 1, Holograph has a couple of amazing map presentation on the Transcontinental Triangulation and the Eastern Oblique Arc at http://www.holoscenes.com/cgi-bin/moin.cgi/HistoricalSurveys. Tim Osborn

Lane: If you are specifically interested in Alabama, I can provide you with a file that lists the center latitude and longitude for each Township in Alabama. Alabama's PLSS system is controlled by 2 Principal Meridians: The St. Stephens Meridian of 1805 and the Huntsville Meridian of 1807. Tim Osborn

The datasheet for PID=NL0720 indicates 2 reference monumunts and one azimuth mark. Did you find any of these? Also, in the datasheet station description it specifically says "STATION IS AN IRON PIPE AND CAP." Since you found a rebar instead of a pipe, I doubt you have found it.