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Using Geoserver, I'm trying to get the correct projection for a map layer that is provided by the State of Idaho. I've tried looking up the EPSG code from http://prj2epsg.org/search. However, the search results throws an error.

Here is the location of the data - https://fishandgame.idaho.gov/ifwis/portal/opendata/controlled-hunt-areas-2015-elk

Here are the results of the .prj file

PROJCS["NAD_1983_Transverse_Mercator",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",2500000.0],PARAMETER["False_Northing",1200000.0],PARAMETER["Central_Meridian",-114.0],PARAMETER["Scale_Factor",0.9996],PARAMETER["Latitude_Of_Origin",42.0],UNIT["Meter",1.0]]

I found this page that should help, but I don't know what it all means.

https://www.idwr.idaho.gov/GIS/IDTM/

5

You can not find an EPSG code, because the data provider does not use any of the CRS registered at EPSG for Idaho.

Alternatively, you can run gdalsrsinfo on the .prj file to get the proj.4 string:

+proj=tmerc +lat_0=42 +lon_0=-114 +k=0.9996 +x_0=2500000 +y_0=1200000 +ellps=GRS80 +units=m +no_defs

You would have to create a custom CRS from that, or use ogr2ogr to reproject the data to a CRS listed by the EPSG.


UPDATE

The projection is now available in GDAL 2.3.1 as EPSG:102605 (although it is really an ESRI projection code). You can get it from gisinternals or the OSGEO4W gdal-dev package, but not yet with OSGEO4W QGIS builds (which is still at GDAL 2.2.4) or Ubuntugis. Debian testing and Ubuntu cosmic have it, older versions not.

The projection is now also included in the EPSG registry as EPSG:8826 NAD83 / Idaho Transverse Mercator. It will take some time until it finds its way in the GDAL release.

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If you google the whole content of the prj file, you usually end up on the description page for that projection on http://www.spatialreference.org

In your case, it comes to this, showing that there is no EPSG code for that particular projection: http://www.spatialreference.org/ref/sr-org/idaho-tranverse-mercator/

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