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Found this benchmark, help me log it

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Does EXIF information really survive the process of uploading a photo to Groundspeak? I saved that photo two different ways and wasn't able to read the EXIF either way.


"releasethedogs," was this marker east of Scottsdale kinda near Sawik Mountain? It looks to me like a boundary marker, and there's a boundary between Section 12 and Section 7 a little ways west of Sawik.



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Just to add a tidbit. That is a typical quarter section corner of the Public Land Survey System. Set by the General Land Office in it looks like 1930. The GLO became part of the Bureau of Land Management when it was formed in 1946, so records of these boundary surveys can be found in the BLM office for the state it is in. These surveys are described in documentary form called field notes and the sections they mark are portrayed on plats, and often shown on USGS topo maps.


The GLO started setting iron post monuments around 1908, the quarter corner monuments are usually 1 in. diam pipes with the brass cap attached and section corners are 2 in. diam. pipes. Before that monuments were more often stone or other natural material.


Occasionally one does have horizontal or vertical control on it, but that would not be the general rule. There is a Waymarking group for PLSS corners.

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For those who develop an interest in the PLSS, Earthpoint software offers a reasonably-priced Google Earth overlay of the BLM grids. Once it's loaded, you have to be zoomed in fairly close to get it started. Aside from its usefulness in narrowing down the likely location of monuments, it sheds light on other geographical phenomena, such as the zigzag portion of the boundary between Churchill and Lyon counties in Nevada.



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My guess is that it's just east of GC57 Geocache.


yes, you are correct southpaw, it is to the east of GC57 (first geocache in AZ)

so from what i gather, i cant log it as a benchmark? that is a drag.


anyways for those that care here is the EXIF data:


Photo information



Feb 11, 2010

2592×1936 pixels – 1562KB

Filename: 2010-02-11 13.07.02.jpg

Camera: Motorola

Model: Droid

ISO: 47

Exposure: 1/238 sec

Aperture: 2.8

Focal Length: n/a

Flash Used: No

Latitude: 33.531113° N

Longitude: 111.580559° W


Judging from your excellent photo, you also seem to have found traces of uranium ore. You might want to go back and stake a claim....



Uranium ore !?!?! how can you tell?


also thanks to everyone for being so helpful.

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I'm confused. I don't see a boundary S12/S7 in the Saguaro Lake area (33.531113° N 111.580559° W). And anyone know what "PB" section numbers represent?




If you're using the Scaredy Cat topo map viewer, then you're looking at Saguaro Lake, which isn't actually where those coords are. Look at the coords in Google Earth (or google maps) and it'll show you a spot a bit to the south and west. If you see the word "Bulldog", you're looking in the right place.

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I'm confused. I don't see a boundary S12/S7 in the Saguaro Lake area (33.531113° N 111.580559° W). And anyone know what "PB" section numbers represent?




"PB" as in Peanut Butter - Peanut Brittle - or something else? I didn't see a reference of PB section numbers in this thread, so I'm don't follow what you are referring to.



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PB is a relatively new thing called a 'protracted block'.


A township protraction is usually only created in an unsurveyed area. Because this type of designation is relatively new it must mean that there is a new protraction in that township. Which would mean that the township to the east was unsurveyed. Protractions are shown on diagrams which may cover part of a township to multiple townships.


A protraction is sort of a paper plan for survey that is used to describe federal lands for leasing purposes. It cannot be used to sell or patent lands. A new form of protraction was created about 15 years or so ago called an 'Amended Protraction Diagram' or 'APD' which provided for creation of some parcels around the edges called 'Protraction Blocks' which are similar to a protracted section roughly a mile square, but they are odd ball.


I am not sure if plats for Arizona are on line or not, they have been scanned. However APD's may or not be included. I would check here:




Once you are equiped with the township and range. If they don't have it you can call Cadastral Survey office in the Arizona BLM State office.


- jlw


PS: Yes it appears that plats for Arizona can be viewed at the sight I gave the link to above. T2N R7E appears to be the township to the west and T2N R8E is to the east and the protraction diagram does not appear to be shown.

Edited by jwahl
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Second PS about S7 on the brass cap. In the normal course of events in the survey of the PLSS that 1/4 corner along the line between two townships would be run first and marked for the sections which are expected to be established later when each township is surveyed. So for a normal township it would be section 7 to the east and 12 to the west.


For some reason the township to the east was never surveyed and so an actual section 7 was never created whereas the township to the west was surveyed and resurveyed and there is a section 12.


Areas of Federal Public Domain lands remain unsurveyed for a number of reasons. One would be that there is no intent to ever sell or 'patent' the land because it has already been designated or 'reserved' for another purpose such as a National Forest, wilderness reserve, National park or the like. Since a complete original survey of a township costs money and takes time, they are/were sometimes not done because there was no necessity.


Later on, particularly if there is some administrative activity like mineral exploration, oil and gas leasing and the like, it may be determined that a protraction will come in handy in order to legally describe lands within these unsurveyed areas. A lot of vacant federal land were protracted in the 1960 era.


Again those protractions are simply diagrams which represent a plan for how the surveys would be done, if done, and were computed from the best knowledge of where the surveyed exterior lines were. One difficulty with them was in figuring out where your lease was by means of them.


The newer APD mentioned above simplified protraction by establishing a fixed geographic coordinate on most of the 'corners' of the protracted sections. No corners are ever set and no field survey is done. Where this cookie cutter fixed grid meets the surrounding surveys protracted blocks are created as sort of a buffer because the exact relationship between the fixed (by coordinates) protracted sections and the existing surveyed lines on the exterior of the area which are very often older surveys and not precisely known.


Reviewing the timeline, the idea was put forth around 1987 or so and officially put in place around 1990 a little further back in time than I said previously.


- jlw


double PS: a lot of these APD's were done for the USFS for some reason so that they could complete their cooperative mapping and updating of the quads with USGS. The fact that these show on the quad leads me to believe that is where these came from.

Edited by jwahl
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