index.html

## index.html
<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no"/>
    <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=true"></script>
    <script type="text/javascript" src="http://github.com/mbostock/d3/raw/v1.8.4/d3.js"></script>
    <style type="text/css">

html, body, #map {
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
}

.stations, .stations svg {
  position: absolute;
}

.stations svg {
  width:50px;
  height:50px;
  padding-right: 100px;
  font: 10px sans-serif;
}

.stations circle {
  fill: brown;
  stroke: black;
  stroke-width: 1.5px;
}

    </style>
  </head>
  <body>
    <div id="map"></div>
    <script type="text/javascript">

// Create the Google Map…
var map = new google.maps.Map(d3.select("#map").node(), {
  zoom: 8,
  center: new google.maps.LatLng(37.76487, -122.41948),
  mapTypeId: google.maps.MapTypeId.TERRAIN
});

// Load the station data. When the data comes back, create an overlay.
d3.json("stations.json", function(data) {
  var overlay = new google.maps.OverlayView();

  // Add the container when the overlay is added to the map.
  overlay.onAdd = function() {
    var layer = d3.select(this.getPanes().overlayLayer).append("div")
        .attr("class", "stations");

    // Draw each marker as a separate SVG element.
    // We could use a single SVG, but what size would it have?
    overlay.draw = function() {
      var projection = this.getProjection();

      var marker = layer.selectAll("svg")
          .data(d3.entries(data))
          .each(transform) // update existing markers
        .enter().append("svg:svg")
          .each(transform)
          .attr("class", "marker");

      // Add a circle.
      marker.append("svg:circle")
          .attr("r", 4.5)
          .attr("cx", 25)
          .attr("cy", 25);

      // Add a label.
      marker.append("svg:text")
          .attr("x", 33)
          .attr("dy", 28)
          .text(function(d) { return d.key; });

      function transform(d) {
        d = new google.maps.LatLng(d.value[1], d.value[0]);
        d = projection.fromLatLngToDivPixel(d);
        return d3.select(this)
            .style("left", (d.x-25) + "px")
            .style("top", (d.y-25) + "px");
      }
    };
  };

  // Bind our overlay to the map…
  overlay.setMap(map);
});

    </script>
  </body>
</html>

## stations.json
{"KMAE":[-120.12,36.98,"MADERA MUNICIPAL AIRPORT",[26,1,2,5,6,3,2,1,2,7,29,12,3]],"KSJC":[-121.92,37.37,"SAN JOSE INTERNATIONAL  AIRPORT",[28,1,1,1,6,10,5,3,2,4,14,21,7]],"KMCE":[-120.50,37.28,"MERCED MUNICIPAL AIRPORT",[29,1,1,3,7,5,2,1,3,6,12,26,5]],"KMER":[-120.57,37.37,"Merced / Castle Air Force Base",[34,1,1,1,4,5,2,1,1,4,17,22,7]],"KAPC":[-122.28,38.20,"NAPA COUNTY AIRPORT",[23,2,1,6,3,3,8,18,11,13,4,3,5]],"KSUU":[-121.95,38.27,"Fairfield / Travis Air Force Base",[13,7,4,3,3,6,4,13,33,4,1,2,7]],"KSQL":[-122.25,37.52,"San Carlos Airport",[18,3,2,2,3,4,3,2,5,17,16,12,12]],"KSNS":[-121.60,36.67,"SALINAS MUNICIPAL AIRPORT",[21,1,1,6,12,3,1,2,9,21,17,5,1]],"KMOD":[-120.95,37.62,"MODESTO CITY CO SHAM FLD",[27,1,1,2,10,5,1,1,1,3,17,24,8]],"KOAK":[-122.23,37.72,"METRO OAKLAND INTERNATIONAL  AIRPORT ",[16,3,3,2,4,6,3,4,9,23,20,6,2]],"KSCK":[-121.23,37.90,"STOCKTON METROPOLITAN AIRPORT ",[21,2,2,3,6,8,2,1,4,15,19,12,4]],"KCCR":[-122.05,38.00,"CONCORD BUCHANAN FIELD",[24,3,2,1,1,5,17,12,9,9,7,6,4]],"KMRY":[-121.85,36.58,"MONTEREY PENINSULA AIRPORT",[26,1,2,9,5,3,4,9,13,14,9,4,1]],"KPAO":[-122.12,37.47,"Palo Alto Airport",[31,3,1,1,2,5,1,1,1,4,10,25,14]],"KSAC":[-121.50,38.50,"SACRAMENTO EXECUTIVE AIRPORT ",[32,1,0,1,3,11,12,16,5,2,4,9,3]],"KHWD":[-122.12,37.67,"HAYWARD AIR TERMINAL",[20,2,7,2,2,6,3,3,6,23,18,6,2]],"KSTS":[-122.82,38.50,"SANTA ROSA SONOMA COUNTY",[46,1,0,1,5,13,10,4,3,3,4,6,3]],"KSMF":[-121.60,38.70,"SACRAMENTO INTERNATIONAL  AIRPORT",[19,2,1,2,4,21,18,8,3,2,5,12,4]],"KNUQ":[-122.05,37.43,"MOFFETT FIELD",[35,3,1,1,4,7,2,1,2,5,6,17,15]],"KRHV":[-121.82,37.33,"San Jose / Reid / Hillv",[35,0,0,1,4,4,2,1,1,10,28,11,1]],"KWVI":[-121.78,36.93,"WATSONVILLE MUNICIPAL AIRPORT ",[44,1,2,3,4,5,7,9,8,4,6,5,2]],"KMHR":[-121.30,38.55,"Sacramento, Sacramento Mather Airport",[21,1,1,2,8,15,12,12,7,4,5,7,3]],"KVCB":[-121.95,38.38,"VACAVILLE NUT TREE AIRPORT",[36,2,1,1,2,6,10,18,10,2,2,5,6]],"KSFO":[-122.37,37.62,"SAN FRANCISCO INTERNATIONAL  AIRPORT ",[13,3,3,2,3,4,4,4,7,31,20,2,3]],"KLVK":[-121.82,37.70,"LIVERMORE MUNICIPAL AIRPORT ",[32,2,7,3,1,1,2,7,9,17,16,2,1]]}