How to properly decouple Structure Map dependency resolver from ASP.NET MVC web project?

Question

While developing web project using ASP.NET MVC, I came up against a coupling problem. When I build custom controller factory (or dependency resolver if using MVC 3), I need this factory to know somehow where to get dependencies from. Here's my code:

//from Global.asax.cs

DependencyResolver.SetResolver(new StructureMapControllerFactory());
class StructureMapControllerFactory: IDependencyResolver {
    Container repositories;

    public StructureMapControllerFactory()
    {
        repositories = new RepositoriesContainer();
    }
    //... rest of the implementation
}
class RepositoriesContainer: Container
{
   public RepositoriesContainer()
   {
      For<IAccountRepository>().Use<SqlAccountRepository>();
      //...
   }
}

StructureMapControllerFactory class is responsible for injecting dependencies into a controller. As I said, it needs to know where to find these dependencies (I mean concrete classes, like services and repositories implementations).

I have a separate class library called MySite.Data, where all the implementation details live. Contracts, like IAccountRepository, live in library MySite.Contracts. Now, if I reference this MySite.Data library directly from MVC project, there will be a dependency between my site and implementation of its data retrieval. The question is how can I remove it? What are best practices in this situation?

I'm sure it does have a bunch of workarounds, just I haven't found any yet.