Using System.Data.Linq in a Razor view

I may have a fundamental misunderstanding of what is going on here, but I'm having an issue looping through a LinqToSQL class in my razor view:

<h3>Owners</h3>
@foreach (var ThisOwner in Prop.PropertyOwnerships.Where(p=p.bIsOwner.Value==true))
{
<div class="ODEditEntry">
...

I'm getting the following error:

Compiler Error Message: CS0012: The type 'System.Data.Linq.EntitySet`1' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Data.Linq, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.

I tried putting @using System.Data.Linq at the top of the cshtml file but it is telling me that Linq doesn't exist in the System.Data namespace. This is obviously not true and, yes, I do have system.data.linq as a reference in my project.

Any Ideas here? Is a import needed? Can I just not do Linq style stuff in my razor views? That would seem....odd?