title: How do I use the DbGeography Spatial Data Type with EF4.1
body: <p>I'm using Entity Framework 4.1 Code First and have been trying to add a field to represent a Geography column.  However, the datatype DbGeography is not recognized.  I've found references to the System.Data.Spatial namespace online, but I can't find out which Assembly contains it. I found one website that said I needed to install the System CLR Types for SQL Server 2008 R2, but when I tried that the installer said I already had a more recent version installed.  I tried adding a few different SqlServer assemblies, but none seemed to work.</p>
  
  <hr>
  
  <p>One may see this error</p>
  
  <blockquote>
    <p>The type or namespace name 'Spatial' does not exist in the namespace
    'System.Data' (are you missing an assembly reference?)</p>
  </blockquote>