Is the “functional” security model the default? I don’t see any way to choose. Or is this outmoded now? Is there a way to limit access not just to “all pages” but to a specific event page or assigned list?

Paul, not yet. Because the “data” model is still in beta, the features are not set enough to put into a video how-to.

Thank you for the quick response. Based on the titles of the security approaches (functional vs data) I can see that the data model is what we would need. Is there a screencast covering the security models?

You can use the data security model to achieve these desired results. The data security model allows you to assign lists to volunteers. Change your security model by going to People > Permissions and clicking the link saying “switch to ‘data’ security model.” Below you will now see the icons for intern/leader/staffer/admin and the level of actions they can take. Now you just need cut lists based upon geography and assign them to specific volunteers.