To get a picture of costs in the entire DMV area, we need to add maps for Virginia and Maryland. Add pages for each state at the top left of your dashboard.

The state-level data is too large to view all at once. it is more useful to filter by counties that are adjacent to Washington, D.C. To add this filter, click Add a Control -- Drop-down list. Place the control box wherever you want it to be on your dashboard. The control field on the right should be set to county_name.

The control box allows viewers to choose which counties to view. We can set the list to default to show counties in the D.C. rmetro region. 

For Virginia, type Arlington, Fairfax, Falls Church, and Alexandria into the "Default selection" box.  For Maryland, try Calvert, Charles, Frederick, Montgomery, and Prince George's counties into the search box. Notice how adding these terms results in these being automatically selected on your control drop-down list.