Projection Files (.prj) for ArcGIS

By | March 8, 2015

esriI’m still reinstalling applications after building my new killer PC. I moved into the Geographic Information Systems (GIS) apps, and I installed Trimble Pathfinder Office. Pathfinder Office is a Swiss army knife of global positioning systems (GPS) software which is used to process data collected by Trimble Global Navigation Satellite System (GNSS) receivers. Pathfinder Office has a data export module that I use to transform my GPS data in ESRI shapefiles.  I always customize my export properties so they create shapfiles with consistent attributes, units, and coordinate system properties.

One aspect of setting up the export coordinate system requires that you point to a projection file (.prj) on your PC or network corresponding to the coordinate system that you wish to use for your exported shapefile.

projection files required by Trimble export

This was always a simple step, because prior to ESRI ArcGIS 10, I just browsed to the C:\Program Files (x86)\ArcGIS\Coordinate Systems directory and then picked the appropriate .prj file.

In ArcMap 10.1 and higher, ESRI no longer installs the 4,000+ projection files as they did in earlier versions. They now use a virtual directory structure that is created by the user, typically something like:

C:\Users\<user>\AppData\Roaming\ESRI\Desktop10.2\ArcMap\Coordinate Systems.

A projection file can be saved in this directory by clicking the View menu –> Data Frame Properties menu –> Coordinate System tab, selecting the current data frame coordinate system or choosing a new coordinate system, and the clicking the gold star to add it to your favorites.

projection files in ArcGIS data frame properties

I primarily only use one projected coordinate system (NAD 1983 UTM Zone 14N) for most of my mapping, so it isn’t too big of a deal. Someone that uses a large number of coordinate systems would have to be patient creating all of their required projection files this way however.

projection files created in ESRI favorites

I am here to make your lives easier though. I still had a copy of ArcGIS 9.3, so I installed it along with the 4,011 projection files. I copied that coordinate system directory to OneDrive so it will always be available to me wherever I am. I am also making it available to you in the Downloads section of this web site.

[download id=”90″ format=”2″]


You can learn more about using coordinate systems in ArcGIS at ESRI’s web site.

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