eir Mapbox account; the
<code><a href="https://walker-data.com/mapgl/reference/add_fill_layer.html" class="external-link">add_fill_layer()</a></code> function then helps users add layers from
those tileset sources. Given that we’ve already tiled our county and
tract data, we can visualize all 3000+ US counties and all 80,000+
Census tracts intelligently on the same map.</p>
<p>The code used below (click “Show code” to view it) uses mapgl to
visualize counties and Census tracts in a scale-dependent man