Just to let you all know, the CU LU file is in ascii format. to get this converted to raster, you have to open up ARCmap

Click on the icon that looks like a toobox on the top of the screen Open the ArcToolbox

Once that is open, open the conversion tools box

This will give you an option of several tools, from these you want to select the tool "to raster"

The option you want to select here is ascii to raster, once you have done this, it will prompt you for the location of the file. when you are looking for the file make sure the extension on the bottom of the callout box says .ASC, and not .txt

Once this is done, instead of giving millions of values, it will have about 11 discreet values between 11 and 97. Urban development is 21 and 23.

Hopefully this gives you some help

John