Can I filter which Leads a particular user can see?

Can I filter which Leads a particular user can see?

Let's say that I have a "Region" field in my Leads and I always populate it with either "North" or "South".  And I have two users: NorthManager and SouthManager.

I would like NorthManager to ONLY see the Leads where Region is equal to "North" and SouthManager to ONLY see the Leads where Region is equal to "South".

Is this possible?  If so, how, please?

[I couldn't see a way to do it in the Leads module.  I thought Reports might work, since I could filter the contents of the Report and also only allow certain users to view it.  However, I discovered that users needed to have the View permission on the Leads module (and thus could view ALL the Leads) in order to see the contents of the Report.]

Any help you can provide would be greatly appreciated!