I am attempting to georeference this parcel map from a local assessor's office.

In doing so, I am using the georeferencer in QGIS 3.4.

I am using the DMS coordinates on the image to reference the corners of the parcels. The format that QGIS requires is as follows: (dd mm ss.ss).

I think the corners on the parcel map are as follows:
Top left corner: N0° 13' 08"E, N89° 52' 06"E
Top right corner: S0° 15' 08"W, N89° 52' 06"E
Bottom left corner: N0° 13' 08"E, S89° 52' 52"
Bottom right corner: S0° 15' 08"W, S89° 52' 52"

I reference the parcel as follows:
Top left corner: X/East = 00 13 08.00, Y/North = 89 52 06.00
Top right corner: X/East = 00 15 08.00, Y/North = 89 52 06.00
Bottom left corner: X/East = 00 13 08.00, Y/North = 89 52 52.00
Bottom right corner: X/East = 00 15 08.00, Y/North = 89 52 52.00

enter image description here

I set the target SRS to EPSG: 4326 enter image description here

When I finish georeferencing the image, I expect it to be in Cochise County, AZ, but it is way off.

I asked the assessor what the image's CRS is and he said, "The mapping system used by the county assessor is based on the U. S. Public Land Survey System (PLSS). This system uses a section, township and range which is tied to the Gila & Salt River Base & Meridian (GSBM)."

How can I georeference this image? Where am I going wrong, or what more information do I need?

  • 2
    you are mistaking survey bearings for coordinates. I can't see any reference corner on this plat as the starting point for the survey. Presumably it's indicated somewhere, but I'm not seeing it. The Cochise County clerk's office has an on-line GIS. You might be able to get the data directly from there.
    – Llaves
    Commented Oct 6, 2020 at 2:47
  • 1
    89 degrees 52 minutes N is very close to the North Pole. The coordinates on the map must mean something else.
    – user30184
    Commented Oct 6, 2020 at 5:35

1 Answer 1


As has been noted in the comments, what you were interpreting to be latitude/longitude coordinates is actually survey traverse measurements.

What you do have for a starting point is the PLSS grid system information. This is the text at the top that says, "Township 15, Range 25, Section 25 SW" with the handwritten note "SW 1/4". Basically the PLSS system divides the US up into a grid system, but since it was created in the 19th century surveying by hand the grid system isn't one big perfect grid across the US, it's a bunch of smaller grid systems squished together. This is where the details about the Gila and Salt River Base and Meridian come in - they tell you which little grid your data is part of.

The PLSS Map Viewer is a useful tool for visualizing the PLSS grid system over imagery, which could help you double check if you have the correct grid square for your location.

Once you are sure you have the correct PLSS location, this PLSS to lat/long converter website can help you get the lat/long coordinates from the PLSS information. Haven't played around with it too much, so I'm not sure how specific/vague you can be for it to work.

Most importantly, you also want to look into surveying plugins for QGIS. This will be particularly helpful for parcels that aren't a full PLSS grid square (i.e. an "L" shaped parcel). A surveying plugin will potentially let you give a starting location (i.e. a known corner location from the PLSS->lat/long converter or a previous parcel), and then build the rest of the sides of the polygon with the surveying information. If you look at each side of the parcel (and of all the subparcels) you have a distance in feet and then a bearing. For example the top side of your parcel is 2083.20ft in a direction of N 89deg 52' 06" E. 90deg would be due east, so this (89deg etc) is a smidgen more northerly of a direction than that.

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