index.html
<html>
<head>
<title>Leaflet Squirrel - Step 1</title>
<link rel="stylesheet" href="//cdn.leafletjs.com/leaflet-0.7.3/leaflet.css"/>
<script src="//cdn.leafletjs.com/leaflet-0.7.3/leaflet.js"></script>
<style>
#map{ height: 100% }
</style>
</head>
<body>
<div id="map"></div>
<script>
var map = L.map('map').setView([39.833, -98.35], 4);
L.tileLayer(
'//{s}.sm.mapstack.stamen.com/((naip,$fff[difference],$fff[@60],$fff[hsl-saturation@90])[multiply],(mapbox-water,$fff[difference],$000[@60],$090d11[hsl-color]))/{z}/{x}/{y}.png', {
attribution: 'Map tiles by <a href=”//stamen.com”>Stamen Design</a>, under <a href=”//creativecommons.org/licenses/by/3.0”>CC BY 3.0</a>. Data by <a href=”//openstreetmap.org”>OpenStreetMap</a>, under <a href=”//creativecommons.org/licenses/by-sa/3.0”>CC BY SA</a>',
maxZoom: 19,
minZoom: 4
}).addTo(map);
</script>
</body>
</html>