I'm working with a shapefile where the latitude and longitude is large.

Here is it bounding box:

> utah_ed@bbox
                min       max
coords.x1  239109.1  671324.5
coords.x2 4101331.7 4651097.8

However, when getting a Utah map from ggmap, the longitude is between (-113, -110) and the latitude is between (39.5, 42.0).

How do I convert them into the same scale so I can plot over them?

  • You have data in projected coordinates, look for the PRJ file for the projection.. To convert to DD (geographic lat/lon) you can use many tools but that depends on what software you have, do you have any spatial software or API to work with? Oct 19, 2017 at 22:07

1 Answer 1


your coords.x1 and x2 are not "large" they're just another "units" (more complicated though), different from lat and long, think of a ruler with inches and centimeteres, you need to convert either of them to the other, with library(rgdal) with something like

coords_man<-SpatialPoints(coords, proj4string = CRS("++proj=utm +zone=14"))

where the .csv file has your coordinates

  • Since the data should be in Utah, utm zone 12 should be the right UTM zone.
    – AndreJ
    Oct 20, 2017 at 6:14
  • 2
    CRS("++proj=utm +zone=14") looks like it has too many plus signs in it.
    – Spacedman
    Oct 20, 2017 at 7:18
  • could be in any of the Utah state planes too - epsg.io/?q=utah
    – Ian Turton
    Oct 20, 2017 at 10:25
  • @Meo you may mark it as answer if it worked
    – Elio Diaz
    Oct 20, 2017 at 17:47

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