JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://code.jquerygeo.com/jquery.geo-1.0a4.min.js"></script>
<div id="map">
    <div id="insetmap"></div>
</div>

CSS

html {
    font:13px/1.231 Calibri, Arial, sans-serif;
    *font-size:small;
}
.info {
    background: #fff;
    border-radius: 8px;
    box-shadow: -4px 4px #444;
    opacity: .8;
    padding: 8px;
    width: 95%;
}
#map {
    position: fixed;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
}
#insetmap {
    border: solid 2px #444;
    position: fixed;
    right: 8px;
    bottom: 8px;
    width: 20%;
    height: 20%;
}

JavaScript

// create a map
      var map = $("#map").geomap({
          center: [-71.0595678, 42.3604823],
          zoom: 9,
          bboxchange: function (e, geo) {
              // whenever the bbox changes, update the inset map's shape
              insetmap.geomap("empty");
              insetmap.geomap("append", bboxToPolygon(geo.bbox));
          }
      });

      // create a smaller map
      // stop interaction (static mode) and add the default service but
      // without an attr property, it's on the main map
      var insetmap = $("#insetmap").geomap({
          center: [-82.0595678, 42.3604823],
          zoom: 6,
          mode: "static",
          services: [{
              type: "tiled",
              src: "http://tile.openstreetmap.org/{{=zoom}}/{{=tile.column}}/{{=tile.row}}.png"
          }]
      });

      // append a shape to the inset map to show the big map's bbox
      insetmap.geomap("append", bboxToPolygon(map.geomap("option", "bbox")));

      function bboxToPolygon(bbox) {
          // a quick function to convert a bbox into a true GeoJSON Polygon
          return {
              type: "Polygon",
              coordinates: [
                  [
                      [bbox[0], bbox[1]],
                      [bbox[0], bbox[3]],
                      [bbox[2], bbox[3]],
                      [bbox[2], bbox[1]],
                      [bbox[0], bbox[1]]
                  ]
              ]
          }
      }