I agree with David Newman. Don’t show me the whole darn planet in the map view, forcing me to zoom in and center the map over my district. I suggest you make it automatically zoom to the level at which all the dots fit, but are most spread out. If that is too much programming, then maybe just allow the user to set a preferred zoom level and map center (though the map center should be autocalculated based on the middle point of all your dots).