This is a Voronoi diagram of the PNW district events scheduled for 2016. It uses green lines to show the region that is closest to each district event, with a black dot for the location of each event. These are approximate.
According to this: http://www.chiefdelphi.com/forums/showpost.php?p=1496615&postcount=19, this will determine what the ‘home event’ assignments will be. Note that I have not seen any official literature confirming this.