JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://maps.google.com/maps/api/js?sensor=false&amp;.js"></script>
<div id="map"></div>

CSS

#map {
  width:500px;
  height:500px;      
}

JavaScript

function pointInPolygon(state, lat, lng) {
    var polyCount = state.length;
    var oddNodes = false;
    var j = 0;
    for (var i = 0; i < polyCount; i++) {
        j++;
        if (j == polyCount) {
            j = 0;
        }
        latitudeBoundry = state[i].lat();
        longitudeBoundry = state[i].lng();
        latitudeBoundry2 = state[j].lat();
        longitudeBoundry2 = state[j].lng();

        if ((latitudeBoundry > lat && latitudeBoundry <= lat || latitudeBoundry2 > lat && latitudeBoundry <= lat)) {
            if (longitudeBoundry + (lat - latitudeBoundry) / (latitudeBoundry2 - latitudeBoundry) * (longitudeBoundry2 - longitudeBoundry) > lng) {
                oddNodes = !oddNodes
            }
        }
    }
    return oddNodes;
}


function initialize() {
    var center_latlng = new google.maps.LatLng(42.354183, -71.065063);

    var options = {
        zoom: 15,
        minZoom: 2,
        maxZoom: 19,
        center: center_latlng,
        mapTypeId: google.maps.MapTypeId.ROADMAP
    };

    map = new google.maps.Map(document.getElementById("map"), options);

    var COLORADO = [
        new google.maps.LatLng(37.0004, -109.0448),
         new google.maps.LatLng(40.9996, -109.0489),
        new google.maps.LatLng(41.0006, -102.0534),
        new google.maps.LatLng(36.9949, -102.0424),
        new google.maps.LatLng(37.0004, -109.0448)
        ];



    var counter = 0;

    //this point is in CO
    if (pointInPolygon(COLORADO, 39.274222, -106.129329)) {
        counter++;
    }

    //this point is not in CO
    if (pointInPolygon(COLORADO, 39.376205, -109.557064)) {
        counter++;
    }

    //this point is not in CO
    if (pointInPolygon(COLORADO, 37.952283, -100.031918)) {
        counter++;
    }

    console.log("counter should be 1 -> counter == " + counter);


    //create a bounds for the zoom level.
    var bounds = new google.maps.LatLngBounds();
    for (var i = 0; i < COLORADO.length; i++) {
       ...