Sometime in the last 30 days (maybe longer), the projections being provided on e.g. SpatialReference.org and EPSG.io are inaccurate for epsg:3418. (Iowa South) and maybe others?

As seen in this map from EPSG, the bounds appear to be way northeast from Iowa (up in Canada). This reflects what I'm seeing downstream, using https://github.com/proj4php/proj4php to convert GeoJSON values, which pulls from SpatialReference.

Screenshot of Canada

Does anyone know where I should be reporting this issue? Is it OSGeo/PROJ, or the Python library powering SpatialReference? I'm not super familiar with all of the fun Geo/projection terms, so I don't really know where to start.

  • looks like the changes where made on 10th January 2024 "Built on 2024-01-10 using PROJ 9.3.0" - would reach out to the devs spatialreference.org/about.html
    – Mapperz
    Commented Jan 19 at 16:40
  • Area of use is just informative so wrong extent does not need to be critical. Could you give an example of some coordinate transformation operation that gives wrong result nowadays?
    – user30184
    Commented Jan 19 at 16:43
  • @user30184 Here's an example of a coordinate in EPSG:3418: 1623863.8131117225, 643763.90620113909 The expected WGS84 is: lat: 41.766901, lng: -93.560676 But today's result is: lat: 44.960581, lng: -79.222403 Commented Jan 19 at 16:49
  • 1
    Thanks @Mapperz - added an issue here to see if it gets in front of the right person: github.com/OSGeo/spatialreference.org/issues/12 Commented Jan 19 at 16:55
  • With Proj 9.3.1 I get from gdaltransform -s_srs epsg:3418 -t_srs epsg:4326 values -93.5606745002133 (lon) 41.7669002221578 (lat).
    – user30184
    Commented Jan 19 at 17:05

1 Answer 1


Update: It was related to the PHP implementation https://github.com/proj4php/proj4php/pull/140

I'm unsure whether it was a bug introduced in the library, or a change in the data upstream. Regardless, the latest version works now.

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